Method and apparatus for releasing connection with local GW when UE moves out of the residential/enterprise network coverage

ABSTRACT

A method, system and device are provided for managing LIPA and/or SIPTO connection releases when UE moves out of residential/enterprise network coverage in case service continuity is not supported for the LIPA/SIPTO PDN connection(s). To address problems caused by not providing service continuity for LIPA/SIPTO PDN connections, the PDN connection/PDP context created in the HeNB/HNB by the MME/SGSN includes context information related to the UE indicating whether such connection is a LIPA PDN connection PDN connection or not. In addition, each UE may be configured to reconnect or not reconnect to the PDN corresponding to a certain APN or service, depending on how the PDN connection was disconnected by the network.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. patent application No.61/387,297, filed Sep. 28, 2010.

FIELD OF THE INVENTION

The present disclosure is directed in general to communications systemsand methods for operating same. In one aspect, the present disclosurerelates to the methods, systems and devices for managing local IP access(LIPA) connection releases resulting from mobility of a user equipment.

DESCRIPTION OF THE RELATED ART

Within the 3rd Generation Partnership Project (3GPP), standards arebeing developed for the interface between the mobile core network and afemtocell which is a small cellular base station, typically designed foruse in a home or small business. Home NodeB (HNB), Home eNB (HeNB) andfemto cell are concepts introduced for Universal MobileTelecommunications System (UMTS) and Long Term Evolution (LTE) evolvedUMTS Terrestrial Radio Access Network (E-UTRAN) to improve indoor andmicro-cell coverage as well as to leverage wireline backhaul to the“home.” A femtocell is widely used outside of 3GPP to mean any cell witha very small coverage, and typically installed in a private premises(either private or corporate or residential/enterprise). The Home NodeB(HNB), Home eNB (HeNB) and femto cell can have a residential orenterprise IP network. The terms HeNB/HNB are used in 3GPP with specificmeanings, i.e. that the cell is a closed subscriber group (CSG) orhybrid cell. A CSG identifies subscribers of an operator who arepermitted to access one or more cells of the public land mobile network(PLMN) but which have restricted access. A H(e)NB subsystem supportsLocal IP Access in order to provide access for IP-capable user equipment(UE) devices connected via a H(e)NB subsystem (i.e. using H(e)NB radioaccess) to other IP capable entities in the same residential IP networkor enterprise IP network. The term macrocell, while not havingsignificance in 3GPP specifications, is widely used to mean a cell otherthan a CSG cell.

One aspect of HeNB/HNB functionality is the ability to restrict accessto particular users. For example, access may be restricted to employeesof the company on whose site the HeNB is deployed, to customers of aparticular coffee shop chain, or (in the case of HeNBs deployed inprivate homes) to individuals. To achieve this functionality, 3GPP hasdefined the concept of the Closed Subscriber Group (CSG). The CSG cellis one which indicates that it is a CSG cell (by means of 1 bitbroadcast in the system information) and broadcasts a CSG ID (also insystem information). A cell can only indicate one (or none) CSG IDs,however multiple cells may share a CSG ID. A UE device may be subscribedto multiple CSGs. The UE may for example may be a mobile terminal suchas, but not limited to a cellular telephone, a personal data assistant(PDA), or a wirelessly enabled computer. A subscription may be temporaryin nature (e.g., a coffee shop allows a customer one hour's access toits CSG).

3GPP standards are also being developed for the concept of selected IPtraffic offloading (SIPTO) which allows internet traffic to flow fromthe femtocell directly to the internet, bypassing the operator's corenetwork. SIPTO is used to offload selected types of IP traffic (e.g.internet traffic) towards a defined IP network close to the UE's pointof attachment to the access network. SIPTO is applicable to trafficoffload for the macro-cellular access network and for the femto cellsubsystem. SIPTO PDN Connectivity indicates a PDP Context or PDNConnection that allows offload of selected types of IP traffic (e.g.internet traffic) towards a defined IP network close to the UE's pointof attachment to the access network. SIPTO is applicable to trafficoffload for the macro-cellular access network and for the femto cellsubsystem.

In addition, standards are being developed for local IP Access (LIPA)which allows an IP-capable UE connected via a femto cell direct accessto other IP-capable devices in the local residential/corporate IPnetwork. LIPA PDN Connectivity indicates a PDP Context (in the case of aGERAN or UTRAN femto cell connected to a GPRS core network) or a PDNConnection (in the case of an E-UTRAN femto cell connected to a GPRScore network) that gives access to services located in the localresidential/corporate IP network of the femto cell subsystem.

In connection with these developing standards, the followingabbreviations and meanings have been developed.

The Connectivity Type indicates the type of connectivity provided for apacket data protocol (PDP) Context or PDN Connection, and applies toboth connectivity established in a macro cell (in which case it can beeither remote connectivity—i.e., with a GGSN/PDN GW located in theoperator core network—or SIPTO connectivity or remote IP access (RIPA)connectivity) and to connectivity established in a H(e)NB (in which caseit can be either SIPTO connectivity or LIPA connectivity).

A Closed Subscriber Group (CSG) identifies subscribers of an operatorwho are permitted to access one or more cells of the PLMN but which haverestricted access (CSG cells).

A CSG Cell is a cell that is part of the public land mobile network(PLMN) broadcasting a specific CSG identity, and that is accessible bythe members of the closed subscriber group for that CSG identity. Allthe CSG cells sharing the same identity are identifiable as a singlegroup for the purposes of mobility management and charging. A CSG Cellis considered to be synonymous of HNB and HeNB.

An Allowed CSG List is a list stored in the network and the UEcontaining all the CSG identity information of the CSGs to which thesubscriber belongs.

A CSG Owner is the owner of one or more H(e)NBs that have beenconfigured as a CSG cell(s) for a particular CSG. A CSG owner can, underthe H(e)NB operator's supervision, add, remove and view the list of CSGmembers.

Local IP Access (LIPA) provides access for IP-capable UEs connected viaa H(e)NB (i.e. using H(e)NB radio access) to other IP capable entitiesin the same residential/enterprise IP network. Traffic for Local IPAccess is expected to not traverse the mobile operator's network exceptH(e)NB.

A LIPA PDN Connection/PDP Context is a PDN Connection or PDP Contextthat gives access to the UE to services located in the localresidential/corporate IP network. The PDN GW/GGSN (or Local GW) isselected in such a way to provide this type of connectivity.Alternatively, a LIPA PDN Connection/PDP context is defined as a PDNConnection/PDP context that provides access for IP capable UEs connectedvia a H(e)NB (i.e. using H(e)NB radio access) to other IP capableentities in the same residential/enterprise IP network. Alternatively, aLIPA PDN connection or LIPA PDP context is a PDN Connection that the MMEauthorizes for connectivity to a PDN GW for a UE connected to a HeNBbased on a request from the UE for LIPA connectivity and based on theCSG ID of the HeNB. Alternatively, a LIPA PDN connection or LIPA PDPcontext is a PDN Connection which was activated by the UE requestingLIPA connectivity type “LIPA” and the MME informing the UE of theconnectivity type provided.

LIPA PDN Continuity refers to the UE having a LIPA PDN Connection/PDPContext while camping or connected in a H(e)NB that maintains theconnection when moving to another H(e)NB or to a macro cell.

An evolved packet core (EPC) functionality (e.g., SGSN, MME, S-GW, PDNGW, GGSN, etc.) is LIPA-aware and/or SIPTO-aware and/orSIPTO-local-aware if the functionality determines that a given PDNconnection or PDP context is a LIPA/SIPTO/SIPTO-local PDN connection orPDP context. Alternatively, the functionality is LIPA-aware and/orSIPTO-aware and/or SIPTO-local-aware if it is configured to managenetwork contexts (e.g. PDN connection/PDP context descriptors andrelated signaling) for LIPA/SIPTO/SIPTO-local connections.

Network address translator (NAT) is a translator that modifies networkaddress information in datagram (IP) packet headers while in transitacross a traffic routing device for the purpose of remapping one IPaddress space into another.

A Packet Data Network (PDN) is a network providing data services, suchas the Internet, Intranet and ATM networks.

A PDN Connection is a connection to a specific PDN identified by aspecific APN.

Remote Connectivity refers to a PDP Context or PDN Connection for whichthe GGSN or the PDN GW, respectively, are selected in the PLMN corenetwork according to current selection mechanisms. Remote Connectivitydoes not include providing SIPTO or LIPA connectivity, but could beproviding RIPA connectivity.

Selected IP Traffic Offload (SIPTO) operations offload selected types ofIP traffic (e.g., internet traffic) towards an IP network close to theUE's point of attachment to the access network. SIPTO is applicable totraffic offload for the macro-cellular access network and for the H(e)NBsubsystem.

SIPTO PDN Connection/PDP Context refers to a PDN Connection/PDP Contextfor which the breakout point (e.g., PDN GW or GGSN) is close to the UE'spoint of attachment to the access network.

SIPTO Local refers to the offload of selected types of IP traffic (e.g.,internet traffic) at the H(e)NB towards the Internet.

SIPTO Local PDN Connection/PDP Context is a PDN Connection/PDP Contextfor which the breakout point is the H(e)NB the UE is connected to andprovides access to the Internet.

Home Node B (HNB) refers to customer-premises equipment that connects a3GPP UE over UTRAN wireless air interface to a mobile operator'snetwork, e.g., using broadband IP backhaul.

Home Evolved Node B (HeNB) refers to a customer-premises equipment thatconnects a 3GPP UE over E-UTRAN wireless air interface to a mobileoperator's network. e.g., using broadband IP backhaul.

A H(e)NB Gateway is a mobile network operator's equipment (usuallyphysically located on mobile operator premises) through which the H(c)NBgets access to mobile operator's core network. For HeNBs, the HeNBGateway is optional.

A Default PDN Connection is the connection to the PDN that the operatorhas set as default for the UE (for a PDP Connection in EPS or a PDPContext in GPRS) (provisioned in the subscriber profile). The UE may notknow the APN for the Default PDN even after the UE attaches to thenetwork and obtains connectivity to the default PDN.

The network architecture model for the support of CSG Cells is describedin 3GPP TR 23.830 (Architecture aspects of Home NodeB and Home eNodeB)and depicted with reference to FIG. 1 which shows an architecture modelfor a Home NodeB access network 100. As depicted, the network 100includes one or more CSG-capable UEs 170 in communication with a HNB 110over reference point Uu 175. The UEs 170 may, for example, be a mobileterminal such as, but not limited to, a cellular telephone, a personaldata assistant (PDA), or a wirelessly enabled computer. The HNB 110 isin communication with a HNB gateway (HNB GW) 120 over reference pointIuh 115. The HNB GW 120 is in communication with mobile switchingcenter/visitor location center (MSC/VLR) 130 over reference point Iu-CS124. The HNB GW 120 is also in communication with serving GPRS SupportNode (SGSN) 140 over reference point Iu-PS 126. A CSG List Server (CSGList Srv) 150 and home location register/home subscriber server(HLR/HSS) 160 are part of a home public land mobile network (HPLMN) 190.Networks that are not the HPLMN 190 on which the UE may operate are avisited public land mobile network (VPLMN) 180. The MSC/VLR 130 and theSGSN 140 are each in communication with the HLR/HSS 160 over referencepoints D 135 and GRs6d 145, respectively. One of the CSG enabled UEs 170is in communication with the CSG List Srv 150 over reference point C1185. A more detailed description of the elements and communicationreference points of FIG. 1 are provided hereinbelow.

HNB 110: The HNB 110 provides the RAN connectivity using the Iuh 115interface, supports the NodeB and most of the radio network controller(RNC) functions and also HNB authentication, HNB-GW discovery, HNBregistration and UE registration over Iuh 115. The HNB 110 secures thecommunication to/from the SeGW.

HNB GW 120: The HNB GW 120 serves the purpose of a RNC presenting itselfto the core network (CN) as a concentrator of HNB connections, i.e. theHNB GW 120 provides concentration function for the control plane andprovides concentration function for the user plane. The HNB GW 120supports Non Access Stratum (NAS) Node Selection Function (NNSF).

Uu 175: Standard Uu interface between the UE 170 and the HNB 110.

Iuh 115: Interface between the HNB 110 and HNB GW 120. For the controlplane. Iuh 115 uses HNBAP protocol to support HNB registration, UEregistration and error handling functions. For the user plane, Iuhsupport user plane transport bearer handling.

Iu-CS 124: Standard lu-CS interface between the HNB GW 120 and thecircuit switched (CS) core network.

Iu-PS 126: Standard Iu-PS interface between the HNB GW 120 and thepacket switched (PS) core network.

D 135: Standard D interface between mobile switching center/visitorlocation center (MSC/VLR) 130 and home location register/home subscriberserver (HLR/HSS) 160.

Gr/S6d 145: Standard Gr interface between serving GPRS Support Node(SGSN) 140 and HLR/HSS 160.

C1 185: Optional interface between the CSG List Server (CSG List Srv)150 and CSG-capable UEs 170. Over-the-air (OTA) signaling is used toupdate the allowed CSG list on a UE 170 with a Release 8 (Rel-8)Universal Subscriber Identity Module (USIM). In some embodiments, OpenMobile Alliance (OMA) Device Management (DM) is used to update theAllowed CSG list on the UE 170 with a pre-Rel-8 USIM.

UEs that are capable of supporting Rel-8 functionality of the 3GPPstandard may support CSG functionality and maintain a list of allowedCSG identities. This list can be empty in case the UE does not belong toany CSG.

Each cell of a HeNB may belong to, at maximum, one CSG. It is possiblefor cells of a HeNB to belong to different CSGs and hence have differentCSG IDs.

The Allowed CSG List is provided as part of the CSG subscriber'ssubscription data to the MME.

The Allowed CSG List can be updated in the UE according to the result ofthe attach procedure, the Tracking Area Update (TAU) procedure, servicerequest and detach procedures or by application level mechanisms such asOMA DM procedures.

The MME performs access control for the UEs accessing through CSG cellsduring attach, combined attach, detach, service request and TAUprocedures.

The UE is notified of the cause of rejection by the network if the UE isnot allowed to access a CSG cell.

When a CSG ID which is not included in the UE's Allowed CSG List ismanually selected by the user, a TAU procedure via the selected CSG cellmay be triggered immediately by the UE to allow MME to perform CSGaccess control.

There is no restriction on Tracking Area Identity (TAI) assignment forE-UTRAN CSG cells. As a result, it is possible that a normal cell(non-CSG cell) and a CSG cell can share the same TAI or have differentTAIs. In addition, it is possible that CSG cells with different CSG IDcan share the same TAI or have different TAIs. It is also possible thatCSG cells with the same CSG ID can share the same TAI or have differentTAIs.

The concept of TAI list applies also for CSG cells. The TAI list mayinclude TAIs related to CSG cells and TAIs related to non-CSG cells. TheUE does not differentiate these TAIs in the TAI list.

For the case of HeNB GW deployment, TAIs supported in the HeNB GW arethe aggregation of TAIs supported by the CSG cells under this HeNB GW.

Several architectures for HeNB CSG Cells will now be described withreference to FIGS. 2-4. Starting with FIG. 2, there is depicted anarchitecture model for a HeNB access network 200 which includes adedicated HeNB GW. In the depicted network 200, a single UE 270 is incommunication with a HeNB 210 over reference point LTE-Uu 275. The HeNB210 is also in communication with a HeNB gateway (HeNB GW) 220 overreference point S1 215. The HeNB GW 220 is in communication withmobility management entity (MME) 230 over reference point S1-MME 224,and is also in communication with serving gateway (S-GW) 240 overreference point S1-U 226. A CSG List Server (CSG List Srv) 250 and homesubscriber server (HSS) 260 are part of a home public land mobilenetwork (HPLMN) 290. Networks that are not the HPLMN 290 on which the UEmay operate are a visited public land mobile network (VPLMN) 280. TheMME 230 is in communication with the HSS 260 over reference point S6a235. The S-GW 240 is in communication with the MME 230 over referencepoint S11 245. The UE 270 is in communication with the CSG List Srv 250over reference point C1 285. A more detailed description of the elementsand communication reference points of FIG. 2 are provided below.

HeNB 210: The functions supported by the HeNB 210 may be the same asthose supported by an eNB (with the possible exception of Non Accessstratum (NAS) node selection function (NNSF)) and the procedures runbetween a HeNB and the evolved packet core (EPC) may be the same asthose between an eNB and the EPC. The HeNB 210 secures the communicationto/from the SeGW 240.

HeNB GW 220: HeNB GW 220 serves as a concentrator for the control plane(C-Plane), specifically the S1-MME interface 224. The HeNB GW mayoptionally terminate the user plane towards the HeNB 210 and towards theS-GW 240, and provide a relay function for relaying User Plane databetween the HeNB 210 and the S-GW 240. In some embodiments, the HeNB GW220 supports NNSF.

S-GW 240: The Security Gateway 240 is a logical function that may beimplemented either as a separate physical entity or co-located with anexisting entity. The S-GW 240 secures the communication from/to the HeNB210.

LTE-Uu 275: Standard LTE-Uu interface between the UE 270 and the HeNB210.

S1-MME 224: The S1-MME 224 interface is defined between HeNB 210 and MME230 if no HeNB GW 220 is used. If HeNB GW 220 is present, as in FIG. 2,the HeNB GW 220 may use an S1-MME interface towards both HeNB (S1 215)and MME (S1-MME 224).

S1-U 226: The S1-U data plane is defined between the HeNB 210, HeNB GW220 and the Serving Gateway (S-GW) 240, depending upon the arrangementof network elements. The S1-U 226 interface from the HeNB 210 may beterminated at the HeNB GW 220, or a direct logical U-Plane connectionbetween HeNB and S-GW may be used.

S11 245: Standard interface between MME 230 and S-GW 240.

S6a 235: Standard interface between MME 230 and HSS 260.

C1 285: Optional interface between the CSG List Srv 250 and CSG-capableUEs 270. OTA is used to update the allowed CSG list on a UE 270 with aRel-8 USIM. OMA DM is used to update the Allowed CSG list on a UE with apre-Rel-8 USIM.

With reference to FIG. 3, there is depicted an architecture model for aHeNB access network 300 which does not include a dedicated HeNB GW. Inthe depicted network 300, a single UE 370 is in communication with aHeNB 310 over reference point LTE-Uu 375. The HeNB 310 is incommunication with a S-GW 340 over reference point S1-U 326, and is alsoin communication with MME 330 over reference point S1-MME 324. A CSGList Srv 350 and HSS 360 are part of a HPLMN 390. Networks that are notthe HPLMN 390 on which the UE may operate are a VPLMN 380. The MME 330is in communication with the HSS 360 over reference point S6a 335. TheS-GW 340 is in communication with the MME 330 over reference point S11345. The UE 370 is in communication with the CSG List Srv 350 overreference point C1 385.

With reference to FIG. 4, there is depicted an architecture model for aHeNB access network 400 which includes a HeNB GW for the C-Plane. In thedepicted network 400, a single UE 470 is in communication with a HeNB410 over reference point LTE-Uu 475. The HeNB 410 is in communicationwith a S-GW 440 over reference point S1-U 426, and is also incommunication with a HeNB-GW 420 over reference point S1-MME 422. TheHeNB-GW 420 is in communication with MME 430 over reference point S1-MME424. A CSG List Srv 450 and HSS 460 are part of a HPLMN 490. Networksthat are not the HPLMN 490 on which the UE may operate are a VPLMN 480.The MME 430 is in communication with the HSS 460 over reference pointS6a 435. The S-GW 440 is in communication with the MME 430 overreference point S11 445. The UE 470 is in communication with the CSGList Srv 450 over reference point C1 485.

Traditionally, the UE connects to services through a remote connectionusing a PDP Context towards a GGSN in the core network in the case of2G/3G, and a PDN Connection to a PGW in the Evolved packet system (EPS).As will be appreciated, PDN connection procedures are described in 3GPPTS 23.401 (“General Packet Radio Service (GPRS) enhancements for EvolvedUniversal Terrestrial Radio Access Network (E-UTRAN) access”) and 3GPPTS 24.301 (“Non-Access-Stratum (NAS) protocol for Evolved Packet System(EPS)”). Additional signal flow information relating to PDN connectivitysetup and handover procedures is described in U.S. patent applicationSer. No. 12/685,651 (filed Jan. 11, 2010) and U.S. patent applicationSer. No. 12/685,662 (filed Jan. 11, 2010) which are each incorporatedherein by reference as is fully set forth herein.

As explained above, 3GPP is introducing the concepts of local IP access(LIPA) and selective IP traffic offloading (SIPTO) to supplement thetraditional way for connecting a UE to services through a remoteconnection (PDP Context towards a GGSN in the core network in the caseof 2G/3G, and a PDN Connection to a PGW in the Evolved packet system(EPS). With LIPA and SIPTO connections, the UE is connected to aHNB/HeNB located in a home or corporate environment to obtain localconnectivity, i.e. connectivity through the IP network local to the HNB(i.e. the (residential or enterprise) IP network in the HNB “home”premises). An example of this scenario is when a given application inthe UE needs to print on a local printer, or an application needs todownload an updated music playlist from a local media server. Severalarchitectures for providing LIPA and SIPTO connections over HNB/HeNBcells will now be described with reference to FIGS. 5 and 6, where thedifference between LIPA connectivity and normal connectivity is alsohighlighted.

With reference to FIG. 5, there is illustrated a schematic diagram of anexample logical architecture network 1000 for use in a HNB cellillustrating Local IP connectivity. The depicted network 1000 issubstantially the same as FIG. 1 with the addition of a Gateway GPRSSupport Node (GGSN) 196 connected to the SGSN 140, a PDN 198 connectedto the GGSN 196, and a home network 104 that has an illustrated coveragearea defined by the circle shape. LIPA PDN connectivity is illustratedfrom the UE 170 through the HNB 110 to the local service 106 via dottedline 108. Normal PDN connectivity via the core network (HNB GW 120, SGSN140 and GGSN 196) is illustrated from the UE 170 to the PDN 198 viadashed line 105.

In the HNB scenarios, a UE 170 determines whether it has access to agiven HNB 110 thanks to the UE 170 having knowledge of its belonging toa specific Closed Subscriber Group (CSG). The operator/owner of an HNB110 creates list of CSGs and provisions the UEs 170, 172 with CSG listsso that the UE 170, 172 determines which HNBs it can connect to.Therefore, a UE 170, 172 that is moving in macro-coverage (i.e. incellular cells not belonging to a CSG/HNB) may come across a CSG/HNBcell 104. The UE 170, 172 would use the CSG information to decidewhether to attempt connection to such HNB 110 or not. CSG information istypically configured in the UE 170, 172 by the operator and candynamically be modified, e.g. using OMA-DM (Device Management). USIMinformation to support LIPA is also foreseen. Some of this informationmay be managed by the H(e)NB hosting party too.

With reference to FIG. 6, there is illustrated a schematic diagram ofthe example logical architecture network 1100 for use in a HeNB cellillustrating Local IP connectivity. The depicted network 1100 issubstantially the same as FIG. 2 with the addition of a PGW 296connected to the S-GW 240, a PDN 298 connected to the PGW 296, and ahome network 204 that has an illustrated coverage area defined by acircle shape. LIPA PDN connectivity is illustrated from the UE 270through the HeNB 210 to the local service 206 via dotted line 208.Normal PDN connectivity via the core network (HeBN 210, HeNB GW 220,S-GW 240 and PGW 296) is illustrated from the UE 270 to the PDN 298 viadashed line 205. In the HeNB scenarios, a UE 270 also determines itsaccess rights to the HeNB network 204 using the CSG list provided by theHeNB 210.

As will be appreciated, the relevant 3GPP specifications in this areainclude 3GPP TR 23.829 entitled “Local IP Access & Selected IP TrafficOffload” (which describes the mechanisms for IP traffic offloading) and3GPP S2-096006 entitled “Terminology update to agreed text in TR 23.8xy”(which introduced LIPA and SIPTO functionalities and architecturalaspects). In addition, 3GPP S2-096050 entitled “LIPA and SIPTO nodefunctions” and 3GPP S2-096013 entitled “Internet offload for macronetwork” set forth the architectural principles for selected embodimentsof the disclosure relating to Local IP Access and Selected IP TrafficOffload based on traffic breakout performed within H(e)NB using a localPDN connection, as well as Local IP Access and Selected IP TrafficOffload at H(e)NB by NAT. 3GPP S2-095900 entitled “ArchitecturalRequirements of Internet Offload” introduced the architecturalrequirement that traffic offload can be performed without userinteraction, and that the impact on the existing network entities andprocedures by introducing traffic offload be minimized.

In addition to the foregoing, 3GPP S2-096013 entitled “Internet offloadfor macro network” introduced an additional SIPTO solution whichsupports SIPTO for UMTS macros and for HNB subsystems. The additionalSIPTO solution is depicted in the schematic diagram of FIG. 7 whichshows an example logical architecture showing a Traffic Offload Function(TOF) 1208 deployed at Iu-PS. In the depicted architecture, the TOF 1208is located at Iu-PS and provides standard Iu-PS interface to the RNC1206 and the SGSN 1210. Selected IP Traffic Offload is enabled by NATand SPI/DPI based on operator policies at different levels (e.g. peruser, per APN, per service type, per IP address, etc). The policies maybe configured via e.g. OAM. One PDN connection or PDP context for bothoffload traffic and non-offload traffic is supported, while alsoallowing use of different PDN connections or PDP contexts for offloadtraffic and non-offload traffic (e.g. by selecting the traffic based onAPN). The TOF 1208 includes a number of functions. First, the TOF 1208inspects both NAS and RANAP messages to get subscriber information andestablish local UE context. The TOF 1208 also decides the offload policyto be applied based on above information (e.g., during attach and PDPcontext activation procedures). In addition, TOF 1208 drags the uplinktraffic out from the GTP-U tunnel and performs NAT to offload thetraffic if offload policy is matched. TOF 1208 may also perform reverseNAT to the received downlink offload traffic and inserts it back to theright GTP-U tunnel.

A local gateway-based architecture solution is also introduced at 3GPPS2-096015 entitled “Local GW Based Architecture” which supports Local IPAccess for H(e)NB subsystem, Selected IP Traffic Offload for H(e)NBsubsystem, and Selected IP Traffic Offload for macro network. Thesolution applies to both types of approaches: with separate APNs forSIPTO and non-SIPTO traffic, and also with common APN(s) for SIPTO andnon-SIPTO traffic. The local gateway solution is depicted in theschematic diagram of FIG. 8 which shows an example logical architecturefor a proposed extension of non-roaming architecture for 3GPP accessesfor SIPTO and LIPA. In the depicted architecture, a Local Gateway (L-GW)1306 is co-located with the (H)eNB 1304. Between L-GW 1306 and PDN GW1310, a Local-GW Extension Tunnel 1326 is configured. The L-GW 1306performs gateway and routing to/from external PDN (e.g. internet,enterprise or home NW) that is equivalent to SGi. In addition, the L-GW1306 performs tunneling of IP packets through the extension tunnel 1326to/from PDN GW 1310 (e.g., based on GTP, PMIP, IP in IP or other). TheL-GW 1306 also performs IP address handling (either IP addressallocation and conveyance to PDN GW, or alternatively reception of IPaddress from PDN GW and NATing), as well as coordination with the (H)eNB1304 on usage of local breakout (trigger eNB for local traffichandling). The L-GW 1306 also implements a decision function on theusage of local breakout for uplink traffic (optionally it can be part ofthe eNB). As will be appreciated, the L-GW 1306 is not a PDN GW shiftedto eNB/E-UTRAN, but encompasses only minimal functionality.

With the L-GW 1306, the functionality of the PDN GW 1310 is enhanced byestablishing the extension tunnel 1326 upon PDN connection establishmentfor APNs matching the criteria for local traffic. In addition, the PDNGW 1310 forwards traffic through extension tunnel 1326 and to/from S5/S8tunnel, and performs IP address handling (either obtain of IP addressfrom L-GW, or alternatively conveyance to L-GW).

At the (H)eNB 1304, there is provided UE access state information forthe cell(s) served by the (H)eNB 1304 to the L-GW 1306. In addition, the(H)eNB 1304 implements a decision function on usage of local breakoutfor uplink traffic (based on APN). With the enhanced architecture shownin FIG. 8, mobility between 3GPP and non-3GPP accesses can be managedsince the PDN GW 1310 is always in the path when the UE 1302 leaves the(H)eNB 1304, meaning that the mobility support function of handovertowards non-3GPP accesses can be handled by the PDN GW 1310 as usual. Asa result, such functionality does not need to be provided as part of theL-GW 1305 or within the (H)eNB 1304. In addition, it is possible toachieve dynamic control for LIPA/SIPTO handling in the PDN-GW 1310 whichis switched on only after the extension tunnel 1326 is set up.

Accordingly, a need exists for improved method, system and device formanaging LIPA connection releases to overcome the problems in the art,such as outlined above. Further limitations and disadvantages ofconventional processes and technologies will become apparent to one ofskill in the art after reviewing the remainder of the presentapplication with reference to the drawings and detailed descriptionwhich follow.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be understood, and its numerous objects,features and advantages obtained, when the following detaileddescription is considered in conjunction with the following drawings, inwhich:

FIG. 1 is a schematic diagram of an example logical architecture for usein a HNB cell;

FIG. 2 is a schematic diagram of an example logical architecture for usein a HeNB cell in which the network includes a dedicated HeNB GW;

FIG. 3 is a schematic diagram of another example logical architecturefor use in a HeNB cell in which the network does not include a dedicatedHeNB GW;

FIG. 4 is a schematic diagram of a further example logical architecturefor use in a HeNB cell in which the network includes a HeNB GW for theC-Plane;

FIG. 5 is a schematic diagram of an example logical architecture for usein a HNB cell illustrating Local IP connectivity;

FIG. 6 is a schematic diagram of the example logical architecture foruse in a HeNB cell illustrating Local IP connectivity:

FIG. 7 is a schematic diagram of an example logical architecture fordeploying Selected IP Traffic Offload at Iu-PS;

FIG. 8 is a schematic diagram of an example logical architecture for aproposed extension of non-roaming architecture for 3GPP accesses forSIPTO and LIPA:

FIG. 9 is a schematic diagram of traffic flows in an HeNB subsystem inwhich the UE has at least a LIPA PDN connection;

FIG. 10 is a schematic diagram of traffic flows in an HeNB subsystem inwhich the UE moves outside of HeBN coverage:

FIG. 11 is a signal flow diagram illustrating a LIPA/SIPTO PDNdisconnect procedure during handover from an HeNB to a target E-UTRANcell when the UE has at least one LIPA/SIPTO PDN connection andadditional PDN connections going through the core network;

FIG. 12 is a signal flow diagram illustrating a LIPA/SIPTO PDNdisconnect procedure for implicitly detaching the UE upon receiving ahandover request at the MME which releases the PDN connections and sendsa Detach Request message to UE;

FIG. 13 is a signal flow diagram illustrating a LIPA/SIPTO PDNdisconnect procedure implemented as part of a service request procedurewhere the MME provides bearers for all EPS bears excluding theLIPA/SIPTO bearers;

FIG. 14 is a signal flow diagram illustrating a LIPA/SIPTO PDNdisconnect procedure where the UE re-attaches to the network after theMME rejects the UE's service request;

FIG. 15 is a signal flow diagram illustrating a LIPA/SIPTO PDNdisconnect procedure where a new PDN connection is triggered in responseto the UE's service request;

FIG. 16 is a signal flow diagram illustrating a LIPA/SIPTO PDNdisconnect procedure where a circuit switched fall back (CSFB) callcauses the MME to send an Initial UE Context Setup message with zeroactive PDN connections to implicitly detach the UE from the network;

FIG. 17 is a signal flow diagram illustrating a LIPA/SIPTO PDNdisconnect procedure where a circuit switched fall back (CSFB) callcauses the MME to send an HO Reject message indicating that the PS HO isnot possible to implicitly detach the UE from the network; and

FIG. 18 is a schematic block diagram illustrating exemplary componentsof a mobile wireless communications device which may be used withselected embodiments of the present disclosure.

DETAILED DESCRIPTION

A method, system and device are provided for managing LIPA and/or SIPTOconnection releases when UE moves out of residential/enterprise networkcoverage in case service continuity is not supported for the LIPA/SIPTOPDN connection(s). In selected embodiments where a UE has only one PDNconnection which is LIPA PDN connection, automatically releasing it whenthe UE leaves the residential/enterprise network coverage will cause theUE to be detached from the network as the UE does not have a PDNconnection. To address problems caused by not providing servicecontinuity for LIPA/SIPTO PDN connection(s), the PDN connection/PDPcontext created in the HeNB/HNB by the MME/SGSN includes contextinformation related to the UE indicating whether such connection is aLIPA PDN connection PDN connection or not. In addition, each UE may beconfigured to reconnect (or not reconnect) to the PDN corresponding to acertain APN or service if the PDN connection was disconnected by thenetwork due to mobility from a H(e)NB (where the UE was connected inLIPA to such PDN) to a target cell (where LIPA continuity is notprovided). In selected embodiments, the UE can be configured to contain(1) an indication of whether any PDN that was disconnected due to lackof LIPA service continuity needs to be reconnected, (2) a list of APNsfor which the PDN needs to be reconnected if the PDN that wasdisconnected due to lack of LIPA service continuity, (3) an indicationof availability of LIPA service continuity. (4) a list of indicators forPDN connection with certain characteristics, (5) an indication ofwhether disconnecting non-LIPA is allowed if emergency call withinsufficient credentials is not allowed, and/or (6) an indication ofwhether a UE retains at least two PDN connections with one of the PDNconnections being to either a particular APN or to a default APN.

Various illustrative embodiments of the present disclosure will now bedescribed in detail with reference to the accompanying figures. Whilevarious details are set forth in the following description, it will beappreciated that the present disclosure may be practiced without thesespecific details, and that numerous implementation-specific decisionsmay be made to the disclosure described herein to achieve the devicedesigner's specific goals, such as compliance with process technology ordesign-related constraints, which will vary from one implementation toanother. While such a development effort might be complex andtime-consuming, it would nevertheless be a routine undertaking for thoseof ordinary skill in the art having the benefit of this disclosure. Forexample, selected aspects are shown in block diagram and flow chartform, rather than in detail, in order to avoid limiting or obscuring thepresent disclosure. In addition, some portions of the detaileddescriptions provided herein are presented in terms of algorithms oroperations on data within a computer memory. Such descriptions andrepresentations are used by those skilled in the art to describe andconvey the substance of their work to others skilled in the art. Variousillustrative embodiments of the present disclosure will now be describedin detail below with reference to the figures.

Ongoing 3GPP discussions have addressed the treatment of LIPA/SIPTO PDNconnection releases associated with UE mobility. In these discussions,there is currently a preference to not provide service continuity for aLIPA PDN connection if the UE moves out of the coverage of theresidential/enterprise network, and instead to release the LIPA PDNconnection. This preference for releasing connections is based on anumber of factors. First, there is a concern that lawful Interceptionwill be applied to local IP resource access if the UE resides in macro(e)NB's coverage and service continuity is maintained. Also, it will bedifficult to establish charging schemes which change as the UE movesfrom H(e)NB to macro (e)NB. There may also be authenticationcomplications involved with maintaining service continuity. Based onthese discussions, Release 10 of 3GPP S1-100316 entitled “Mobility forLocal IP Access (LIPA)” and of 3GPP S1-100321 entitled “SIPTOrequirements common for macro network and H(e)NB subsystems” specifiesthat mobility of a LIPA connection to macro network is not supported,whereas mobility of the LIPA connection between H(e)NBs in the sameresidential/enterprise network is supported/required. In addition,Release 10 of 3GPP S1-100321 entitled “SIPTO requirements common formacro network and H(e)NB subsystems” specifies that mobility of a SIPTOconnection within the macro network shall be supported, and mobilityfrom H(e)NB to macro and between H(e)NB may be supported.

In view of the preference against maintaining service continuity forLIPA connections when the UE leaves the residential/enterprise networkcoverage, there are a number of different problems created resulting inunwanted UE disconnections. As explained more fully below, these releaseproblems have multiple dimensions, including problems with PS serviceswhen there is UE mobility in connected mode, problems triggered by CSFBprocedures when there is UE mobility in connected mode, and problemswith or without ISR when there is UE mobility in idle mode. Indiscussing these problems, consideration should be given to LIPAmechanisms which also work for pre-Release 10 UEs (i.e., UEs that arenot aware of LIPA connectivity, such as occurs when the network providesLIPA connectivity to the UE based on subscription profile or networkdecision, without the UE being aware of such decision). For such UEs,NAS signaling and mechanism cannot be modified in order to resolve theidentified problems.

For purposes of illustrating the UE disconnect problem, reference is nowmade to FIGS. 9-10 which schematically illustrate the release of a LIPAPDN connection as the UE moves outside the HeNb enterprise networkcoverage, where the term “PDN connection” refers both to a PDNConnection involving a HeNB and a PDP Context involving a HNB unlessexplicitly indicated. In particular, FIG. 9 is a schematic diagram oftraffic flows in an HeNB subsystem 1400 in which the UE 1416 has aLIPA/SIPTO PDN connection 1430 and a core network (CN) PDN connection1432. With the LIPA/SIPTO PDN connection 1430 established, user planetraffic for LIPA and SIPTO does not go through the core networkconnection 1432. Instead, the traffic goes from UE 1416 through theLocal eNB 1422. Local S-GW 1424, and Local P-GW 1426, which areillustrated to all be collocated in HeNB 1420, as indicated with line1430. If the UE 1416 has an additional, non-LIPA, non-SIPTO PDNconnection, the traffic goes through the HeNB-GW 1410, S-GW 1408, andP-GW 1406 to the core PDN 1404 as indicated with line 1432. Since thesecond PDN connection 1432 can be released at any time (e.g., due topre-defined policy or UE configuration), there are times when the UE1416 has only one PDN connection when connected to the H(e)NB 1420, andsuch PDN connection is a LIPA PDN connection 1430.

To illustrate the UE disconnect problem, reference is now made to FIG.10 which depicts a schematic diagram of traffic flows in an HeNBsubsystem 1500 in which the UE 1416 moves outside of HeBN coverage whenit has only a LIPA PDN connection. In this case, the reference to moving“outside the H(e)NB” indicates both case of the UE moving from a H(e)NBcell to macro cell coverage, and the case of the UE moving betweenH(e)NB cells for which LIPA PDN continuity is not supported (e.g.H(e)NBs with different CSGs). It may be that LIPA PDN continuity is notsupported between any H(e)NB cell. Thus, FIG. 10 illustrates that the UE1416 moves towards a second position 1516 where there is macro coverage,though the UE 1416 could also move to another H(c)NB for which LIPA PDNcontinuity is not supported. As soon as the MME 1414 detects that the UEis not connected to the H(e)NB 1420 (e.g. the UE has moved to adifferent cell where LIPA continuity is not supported), the MME 1414releases the LIPA PDN connection 1430 since there is no requirement ofmaintaining LIPA PDN connectivity. As a result, there is no PDNconnection for the UE 1516. As described more fully below, the MME 1414can detect that the UE 1516 is out of coverage of the H(e)NB 1420 basedon a variety of detection mechanisms, such as when the UE 1516 performsa Tracking Area Update (TAU) or Routing Area Update (RAU) from adifferent cell, or when the UE 1516 responds to paging from a differentcell, etc.

In E-UTRAN, a UE has to maintain at least one PDN connection for the UEto be considered attached to the network. If there is no PDN connection,the UE is detached from the network. FIG. 10 shows how the disconnectproblem arises when a UE 1416 has only a single, active LIPA PDNconnection 1430, and the MME 1414 releases the LIPA PDN connection 1430upon detecting that the UE 1416 has moved to a new position which is notconnected to the H(e)NB 1420 anymore. When detachment occurs, the UE1516 may not know why it is being detached and why the LIPA PDNconnection 1430 is being released, and is then forced to re-attach tothe network. This issue applies both for NAS idle mode mobility and NASconnected mode mobility. As will be appreciated, while the foregoingdiscussion refers to LIPA PDN connections, the same challenges apply toa LIPA PDP Context (in case of HNB) or the SIPTO Local connectivity,unless explicitly indicated. And though not explicitly shown, it willalso be appreciated that similar problems arise when UE mobility is fromthe H(e)NB 1420 towards GERAN/UTRAN (i.e. involving a SGSN), in whichcase the active PDP context (corresponding to the LIPA connection) needsto be deactivated, even if the UE does not need to be detached.

In this framework, a number of problem cases associated with LIPAconnection releases are identified and discussed in relation to FIG. 10more fully below. In addition, solutions for managing the variousconnection release problems are identified and discussed as set forthbelow.

Mobility In Connected Mode There a number of problem cases that arise inthe case of an active handover where the UE has NAS connected modemobility.

In an example problem case, a connected mode UE 1416 has a LIPA PDNconnection or SIPTO connectivity/SIPTO PDN connection 1430. As theconnected mode UE 1416 moves out of the HeNB coverage 1420 (which isdirectly connected to the residential/enterprise network 1402) to asecond position 1516 at a target E-UTRAN cell (e.g., eNB cell 1412 oranother HeNB cell for which LIPA continuity is not supported), thesource HeNB 1420 makes a decision to handover (HO) the UE to the targetcell 1412 based on the measurement reports from the UE 1516. The HeNB1420 sends a HO REQUIRED message to the MME 1414. As the HO REQUIREDmessage contains a Target ID, the MME 1414 determines that LIPA/SIPTOservice shall not be continued at the target cell 1412 (e.g. based onthe fact that the target cell is a macro cell or a H(e)NB in a differentCSG). Based on this determination, the MME 1414 releases the LIPA/SIPTOPDN connection 1430, but the existing specifications do not specify howthe MME 1414 handles the LIPA/SIPTO PDN connection release.

In another problem case, a connected mode UE 1416 is handed over fromHeNB 1420 to a GERAN/UTRAN cell (not shown) for which LIPA PDNcontinuity shall not be supported. An example would occur when a UE 1416having only a LIPA PDN connection 1430 performs an IRAT HO towardsGERAN/UTRAN where LIPA continuity is not supported. In this case, the UEmay become detached from the network or without PDP contexts if the LIPAPDN connection is released, but the existing specifications do notspecify how to handle the IRAT HO. Also, if the UE 1416 has other PDNconnections in addition to the LIPA PDN connection 1430 in the sourcecell, the LIPA PDN connection 1430 needs to be disconnected during thisIRAT HO. The context information between network (SGSN) and UEcontaining information on the active PDN connections/PDP contexts mightbe out of synch for a while until a new RAU is performed by the UE andthe context is synchronized between the UE and the SGSN. In cases wherethe context is out of synch, the UE incorrectly considers the PDPcontext corresponding to the LIPA connection still active.

In another problem case, a connected mode UE 1416 moves from HNB cell orcoverage (not shown) to a target (e.g. GERAN/UTRAN) cell for which LIPAPDN continuity is not provided. An example would occur when UE is in HNBcoverage and it has LIPA/SIPTO PDP context. If service continuity is notsupported, the PDP context will be released when the SGSN detect thatthe UE moved out of HNB's coverage. However, the context informationbetween network (SGSN) and UE containing information on the active PDNconnections/PDP contexts might be out of synch for a while until a newRAU is performed and the context is synchronized between the UE and theSGSN. Due to the out-of-sync context, the UE in the meanwhile considersthe PDP context corresponding to the LIPA connection still active.

Mobility for NAS-Idle UE There a number of problem cases that arise whenthe LIPA connection is disconnected during idle mode mobility and the UEenters NAS connected mode after performing idle mobility outside theH(e)NB.

In a first problem case, the UE 1416 moves from a HeNB cell coverage1420 to a second position 1516 at a target cell 1412 (e.g., an eNB or anHeNB cell) for which continuity shall not be provided. After moving tothe target cell, the UE 1516 may perform a SERVICE REQUEST in a target(e.g., an E-UTRA) cell which is not directly connected to theresidential/enterprise network. On receiving SERVICE REQUEST (SR) fromthe UE via the target cell, the MME 1414 determines it cannot servicethe SR and needs to release the LIPA PDN connectivity 1430. The MME 1414releases the LIPA PDN connectivity 1430 by rejecting the service requestand disconnecting the LIPA PDN connectivity if the UE has other activePDN connections. On the other hand, if the UE has only LIPA PDNconnection before it enters ECM-IDLE mode, a release of the LIPA PDNconnection results in UE not having any active PDN connections left,resulting in the UE being detached from the network by the MME withoutthe UE being correctly informed since the current specifications do notrequire that the MME indicate why the UE is being detached.

In another problem case, the UE 1416 moves from a HeNB 1420 toGERAN/UTRAN (not shown). In this case, the IDLE mode UE performsTracking Area Update (TAU) in an E-UTRAN cell where LIPA servicecontinuity is not provided. In particular, the UE will perform TAU inIDLE mode when (1) the UE enters into a new Tracking Area (TA) that isnot in the list of TAIs that the UE obtained from the MME at the lastregistration (attach or TAU); and (2) the periodic TA update timer hasexpired. If the target cell is not directly connected to theresidential/enterprise network when the UE performs the TAU, the MMEneeds to disconnect the active LIPA PDN connection, but the currentspecifications do not specify how the MME behaves in the presence ofLIPA connections since the MME needs to release such PDN connections.

In another problem case, the UE moves from a HNB to GERAN/UTRAN. In thiscase, the IDLE mode UE (which has at least one LIPA PDN connectionthrough HeNB) performs a Routing Area Update. In particular, the UEperforms RAU when the UE enters into a new Routing Area (RA), and whenthe RAU timer expires. The new SGSN sends a CONTEXT REQUEST message tothe old MME during the RAU, and the MME responds with a CONTEXT RESPONSEmessage. Upon determining that the UE has moved to a cell for which LIPAPDN continuity cannot be supported, the network disconnects the LIPAconnection, but the current specifications do not specify whether theMME or SGSN shall trigger the disconnection and how.

Delay In Discovery Loss of Connectivity in Active Idle MobilityThere area number of problem cases that arise from idle mode mobility when thereis a delay in discovering that connectivity has been lost, with orwithout Idle mode Signaling Reduction (ISR).

In an example problem case, the UE 1416 moves between a HeNB 1420 and aneNB 1412, or between a HNB and macro GERAN/UTRAN, or between HeNBs(respectively HNBs) belonging to different CSGs and for which LIPAcontinuity shall not be provided. If the UE moves in idle mode withinthe Routing Area (RA), Tracking Area (TA), the UE does not perform NASsignaling to register its location with the network. If there is asignificant delay before the UE performs any NAS signaling or the UEtransmits data, the UE does not realize it has lost connectivity, whichcan be a problem, such as for push services when the data to bedelivered to the UE cannot be delivered.

In another problem case, the UE moves from a HeNB to a GERAN/UTRAN cellwhere ISR is active. When idle mobility is performed by the UE from theH(e)NB to a cell for which LIPA PDN connectivity shall not be supportedand ISR is active and the UE moves within the ISR area, the UE does notperform NAS signaling to register its location with the network, andtherefore it may be a long time before the UE performs any NAS signaling(unless it needs to transmit data) and before the UE realizes it haslost connectivity. Such loss of connectivity can be a problem for pushservices since the data to be delivered to the UE cannot be delivered.In addition, if the UE was using a push-service that used the LIPA PDNconnection or was using the default bearer of the LIPA PDN connection totransport the data to the UE, the UE will not be able to receive anypushed data until it realizes it has been disconnected and until it hasperformed recovery action, such as re-attaching. Since a RAU (that willsynchronize the UE and the SGSN contexts) or keep alive mechanisms ofthe push-service may happen long after idle mode mobility, the UE willnot receive any data pushed from the push-service, whereas if the UE hadbeen informed of the disconnection of the LIPA PDN, it could havereconnected to the push service as appropriate from the target cell witha new PDP context.

Delay In Discovery Loss of Connectivity in Active Mode MobilityThere anumber of problem cases that arise from active mode mobility when thereis a delay in discovering that connectivity has been lost.

In an example problem case, the UE in connected mode moves from HeNB toGERAN/UTRAN when ISR is active, resulting in a delay in discovery ofloss of connectivity. This problem exists if a UE that performed theinter-RAT HO and finds itself without RABs for a given PDP context isallowed to still consider the PDP context active. When handover isperformed by a UE that is active for a non-LIPA PDN from the H(e)NB cellcoverage to a target (e.g., GERAN/UTRAN) cell wherein LIPA PDNconnectivity is not supported, the PDP context corresponding to the LIPAPDN connection is disconnected. When ISR is active, the UE will notperform the RAU at the end of the handover if the handover is towards aRA in the ISR area. However, unless the UE is informed immediately, theUE may believe the PDP context corresponding to the LIPA PDN is stillconnected since, even if there are no RABs active for such connection,the UE still believes the PDP context is active. If the UE was usingsome push-service over the LIPA PDN connection, the UE will not be ableto receive any pushed data until it realizes it has been disconnected.Also, since a RAU (that will synchronize the UE and the SGSN contexts)or keep alive mechanisms of the push-service may happen after along-while from the handover, the UE will lose any data pushed from thepush-service, whereas if the UE had been informed of the disconnectionof the LIPA PDN, it could have reconnected to the push service asappropriate from the target cell with a new PDP context.

In another problem case, the UE in connected mode moves from HNB cellcoverage to macro (e.g. GERAN/UTRAN) cell coverage, resulting in delayin discovery of loss of connectivity. If the UE performs handover fromHNB to a target GERAN/UTRAN cell wherein LIPA PDN connectivity is notsupported, the PDP context is disconnected. However, the UE may notperform a RAU as part of the handover, in which case the UE and the SGSNare not synchronized with respect to the active PDP context information.

Delay In Disconnection For Idle Mode MobilityThere is a timing-relatedproblem which is orthogonal to the other problem cases, and the solutionmay benefit both idle mode mobility and active mode mobility. In thiscase, when the UE 1416 moves outside the coverage of the H(e)NB 1420,the LIPA connection is released upon detection, and then re-establishedwhen the UE 1416 moves back within the coverage of the H(e)NB 1420.However, there may be situations where the UE 1416 may return to theH(e)NB 1420 soon, or may keep moving back and forth between the H(e)NB1420 and the macro coverage. In these scenarios, the LIPA connectionwill be established and released repeatedly, resulting in significantsignaling overhead. As a result, it may be desirable to delay therelease of the LIPA connection when the UE 1416 moves outside thecoverage of the H(e)NB 1420 in order to optimize the scenario where theUE 1416 returns to the H(e)NB 1420 relatively quickly.

Handover to GERAN/UTRAN triggered by Circuit Switched FallbackThere anumber of problem cases that arise when a UE connected to a HeNB can becombined attached for CSFB services, such as when handover toGERAN/UTRAN is triggered by CSFB.

In an example problem case, the UE can have a LIPA PDN connection andzero or more non-LIPA PDN connections through the core network. When theCSFB is triggered for Mobile Originated (MO) or Mobile Terminated (MT)services, a PS HO of the data bearers may be triggered by the HeNB andis allowable by the network because the target cell supports DTM and thePS HO as part of the CSFB procedure. In this case, the network handsover the non-LIPA PDN connections and disconnects the LIPA PDNconnections or, if there are only LIPA PDN connections, the MME rejectsthe PS HO. If the MME rejects the PS HO, CSFB for either MO or MT willconsequently fail. In case the PS HO is possible, but the UE or networkfails to support DTM, then upon initiating conditions, the GERAN PSbearers will be suspended. If the target cell is a GERAN cell and DTM isnot supported in the target cell, the UE will suspend the PS bearers(including the ones corresponding to the LIPA PDN connection). Once theCS service that triggered the CS fallback is terminated, the UE may moveback to E-UTRAN and resume the PS bearers, or may stay in GERAN andresume the PS bearers. If the UE moves back to the original H(e)NB, thenthe LIPA PDN connection can be resumed based on current CSFB and EPSmechanisms. For example, when the UE performs NAS signaling towards theMME (e.g., with a Service Request or TAU), the MME resumes the suspendedbearers.

In another problem case, the UE can have a LIPA PDN connection and zeroor more non-LIPA PDN connections through the core network. When the CSFBis triggered for MO or MT services, a PS HO of the data bearers may notbe performed. If the PS HO is not performed as part of the fallbackprocedure and the UE has suspended the PS bearers, and if the UE movesback to E-UTRAN, then the UE performs NAS signaling (e.g., ServiceRequest or TAU) to the MME. The UE might move back to a target E-UTRANcell which is different from the original HeNB cell. Such target E-UTRANcell can be a macro cell or a HeNB with a different CSG ID. Assumingthat service continuity (i.e., mobility) for a LIPA PDN connection isnot allowed between the original HeNB (i.e., where the LIPA PDNconnection was created) and the target HeNB, then the MME ensures thatthe LIPA PDN connection is disconnected. Also, if the target E-UTRANcell is a macro cell, then the MME ensures that the LIPA PDN connectionis disconnected.

Maintaining LIPA PDN Connectivity In Future NetworksIn post release 10networks, LIPA continuity will be enabled, so there will be problemsassociated with maintaining LIP PDN connectivity. In such future cases,a UE will need to know whether it is connecting to a network thatsupports LIPA continuity or not. Therefore, a UE cannot know whether,upon moving outside the coverage of a H(e)NB, session continuity isprovided or not.

In view of the foregoing problem cases associated with LIPA connectionreleases, there are described and disclosed herein a number of solutionsthat may be applied to manage the identified connection releaseproblems. For example, MME-initiated PDN connection release proceduresmay be combined with handover procedures for releasing a PDN connectionwhen the UE moves outside the coverage of the H(e)NB in most cases (andsimilarly the SGSN-initiated PDP context deactivation procedure).However, there are other solutions disclosed hereinbelow wherein, uponcreation of a PDN connection/PDP context in a HeNB/HNB, the MME/SGSNstores in the context information related to the UE an indication ofwhether such connection is a LIPA PDN connection PDN connection or not.In addition, the solutions include configuring the UE (e.g. by theoperator or the user) on whether to reconnect the PDN corresponding to acertain APN or service if, due to mobility from a H(e)NB where the UEwas connected in LIPA to such PDN to a target cell for which LIPAcontinuity is not provided, such PDN connection was disconnected by thenetwork. Alternatively, the UE may be configured to not reconnect thePDN that was disconnected due to UE mobility.

Description of Embodiments

In selected embodiments, the operator configures the UE using an OMA DMmanagement object (MO) to contain an indication of whether any PDN thatwas disconnected due to lack of LIPA service continuity needs to bereconnected. The UE may also be configured to contain a list of APNs forwhich the PDN needs to be reconnected if the PDN that was disconnecteddue to lack of LIPA service continuity. In other embodiments, the UE isconfigure to contain an indication of availability of LIPA servicecontinuity (i.e., only between CSG cells for which the UE is a member ofthe CSG or if not roaming or if mobility to macro occurs or if mobilityto macro occurs+open CSG cells occurs). By default, this indication canbe set to some value, e.g. to no LIPA service continuity available. TheUE may also be configured to contain a list of indicators for a PDNconnection with certain characteristics (i.e., an indication the PDNconnection can be used for IMS or an indication requesting to receiveP-CSCFs in the response message from the network). A configured UE mayalso contain an indication of whether disconnecting non-LIPA is allowedif emergency call with insufficient credentials is not allowed, and/oran indication of whether a UE retains at least two PDN connections whereone of the PDN connections is to either a particular APN or to a defaultAPN (known to terminate by a non PGW) when not in PS mode 2 ofoperations.

In selected embodiments, when the UE activates a LIPA PDN connection,the MME stores the pair of CSG ID and the APN for the LIPA PDNconnection where a LIPA PDN connection is activated at the CSG ID cell.In other embodiments, when the UE activates a LIPA PDP context, the SGSNstores the pair of CSG ID and the APN for the LIPA PDP context where theLIPA PDP context is activated at the CSG ID cell. In some embodiments,the UE activating a LIPA PDN connection or the UE activating a LIPA PDPcontext includes the UE sending a PDN connection request to the MME orthe MME receiving a PDN connection request from the UE or the UE sendingan attach request to the MME or the MME receiving an attach request fromthe UE or the UE sending a PDP context request to the SGSN or the SGSNreceiving a PDP context request from the UE.

As used herein, a LIPA PDN connection is a PDN Connection that the MMEauthorizes for connectivity to a PDN GW for a UE connected to a HeNBbased on a request from the UE for LIPA connectivity and based on theCSG ID of the HeNB. Alternatively, a LIPA PDN Connection is a PDNConnection which was activated by the UE requesting LIPA connectivitytype “LIPA” and the MME informing the UE of the connectivity typeprovided.

In this solution, the TAU procedure is always initiated by the UE and isused for a number of purposes, including synchronizing the UE EPS bearercontext with the MME EPS bearer context for UE mobility where the sourcecell is a CSG cell and the target cell is not a CSG cell, when the UEhas at least one LIPA PDN connection. The TAU procedure is also used tosynchronize the UE EPS bearer context with the MME EPS bearer contextfor UE mobility where the source cell is a CSG cell and the target cellis a CSG cell, and where the target cell's CSG-ID is not the sourcecell's CSG-ID, when the UE has at least one LIPA PDN connection.

Embodiments: UE shall not initiate PDN Disconnect Requestin accordancewith selected embodiments, a solution for managing LIPA connectionreleases is to ensure that the UE always maintains at least one PDNconnection through the core network if the LIPA service continuity isnot supported. In selected embodiments of this solution, a UE isconfigured so that, if the UE has a LIPA PDN connection, the UE shallnot initiate PDN DISCONNECT REQUEST/DEACTIVATE PDP CONTEXT REQUEST if(1) LIPA service continuity is not supported for the UE, and (2) thedisconnection results in one or more active LIPA PDN connections only.

As will be appreciated, this solution may be implemented in any Release10 UE to handle the scenarios of a Release 10 UE being connected to aRelease 10 network. If the UE connects to a Release 11 network thatsupports LIPA continuity, the UE can have LIPA continuity. The solutionis not applicable for pre-Release 10 UEs, and does not apply toscenarios in which the UE is provided (e.g. per operator decision) onlywith LIPA connectivity.

Embodiments: Detach the UE during handoverIn accordance with selectedembodiments, another solution addresses the case of connected modemobility from HeNB to macro E-UTRAN or another HeNB for which LIPAcontinuity is not supported. In this solution, the MME implicitlydeactivates the LIPA PDN connection during the handover between a HeNBand a target E-UTRAN cell when LIPA continuity shall not be supported.Alternatively, the MME explicitly deactivates the LIPA PDN connectionafter the handover is performed. In this solution, the UE detects thatit has lost LIPA PDN connection since the RABs for that PDN will not bepresent in the target cell.

The applied assumptions in this example are that (1) Service Continuityfor the LIPA is not supported, (2) UE is in ECM-CONNECTED mode, (3) HOshould be performed due to the UE's mobility, (4) Target cell belongs toa macro eNB or another HeNB that is not connected to theresidential/enterprise network (other CSG), (5) MME relocation is notinvolved, and (6) UE has at least two PDN connections: one is LIPA PDNconnection another is a PDN connection through core network.

The disclosed solutions in these embodiments provide a way to handle S1based HO procedure between HeNB and the target E-UTRAN cell when the UEhas at least one LIPA/SIPTO PDN connection and additional PDNconnections going through the core network. If MME relocation is neededfor the HO, MME relocation happens right after step 16-1 (described inFIG. 11), and it does not affect the rest of the procedure.

Implicit Deactivation of the LIPA PDN Connection During the Handover

In a first embodiment described with reference to the signal flowdiagram in FIG. 11 where the UE 1602 has one of the PDN connections thatis a LIPA/local SIPTO connection, the MME 1608 performs the handover,but the MME 1608 does not allow the allocation of RABs for the LIPA PDNconnection in the target cell. The MME 1608 does not perform anyexplicit NAS signaling to the UE 1602 to deactivate the LIPA PDNconnection. After the handover, the UE 1602 automatically releases theLIPA PDN connection since no RABs have been allocated for it. For Rel.10 UEs and subsequent releases, the UE detects that the PDN connectionfor which no RABs have been allocated is the LIPA connection and decideswhether to request a new PDN for that APN based on policies orconfiguration information, such as may be provided by the operator orthe user.

In operation, when the HeNB 1604 triggers the handover to a target cellby sending the handover request to the MME 1608 which includes theinformation on the target cell, the MME 1608 determines that there is anactive PDN connection that is a LIPA PDN connection based on the UEcontext information in the MME (including subscription information withLIPA indications, current CSG, current status of LIPA connections, etc.)and the information on the target cell (e.g. technology type, CSG ID).In addition, the MME 1608 determines that LIPA PDN continuity cannot besupported towards the target cell. To implicitly deactivate theconnection, the MME 1608 does not request the allocation of RABs for theLIPA PDN connection in the target cell during the handover preparation.In this way, the UE 1602 performs the handover and detects that no radiobearers have been allocated in the target cell for the LIPA PDNconnection. In this way, the UE 1602 determines that the LIPA PDNconnection has been released. In addition, the UE 1602 determineswhether the PDN connection needs to be reactivated in the target cellbased on configuration information or operator policies or userpolicies.

In the depicted signal flow 1600 shown in FIG. 11, the first or sourceHeNB 1604 sends Handover Required (Direct Forwarding Path Availability,Source to Target transparent container, target eNB Identity, target TAI,SlAP Cause) to the MME 1608 at signal flow 16-1. At signal flow 16-2,MME 1608 determines that service continuity is not supported for theLIPA/SIPTO PDN connection, and the MME 1608 initiates PDN disconnectionprocedure for all the LIPA/SIPTO PDN connections.

At signal flow 16-3, the MME 1608 sends a Handover Request (EPS Bearersto Setup, AMBR. S1AP Cause, Source to Target transparent container,Handover Restriction List) message to the target eNB 1606. This messagedoes not contain the EPS bearers belonging to the released LIPA/SIPTOPDN connections. This message creates the UE context in the target eNB1606, including information about the bearers, and the security context.For each EPS Bearer, the Bearers to Setup includes Serving GW addressand uplink TEID for user plane, and EPS Bearer QoS. In reply, the targeteNB 1606 sends a Handover Request Acknowledge (EPS Bearer Setup list,EPS Bearers failed to setup list Target to Source transparent container)message to the MME 1608 at signal flow 16-4. The EPS Bearer Setup listincludes a list of addresses and TEIDs allocated at the target eNB fordownlink traffic on S1-U reference point (one TEID per bearer) andaddresses and TEIDs for receiving forwarded data if necessary.

At signal flow 16-5, the MME 1608 sends a Handover Command (Target toSource transparent container, Bearers subject to forwarding, Bearers toRelease) message to the HeNB 1604. The Bearers subject to forwardingincludes list of addresses and TEIDs allocated for forwarding. TheBearers to Release includes the list of bearers to be released.

At signal flow 16-6, the HeNB 1604 constructs and sends the HandoverCommand to the UE 1602 using the Target to Source transparent container.Upon reception of this message, the UE 1602 will remove any EPS bearersfor which it did not receive the corresponding EPS radio bearers in thetarget cell. After the UE 1602 has successfully synchronized to thetarget cell, it sends a Handover Confirm message to the target eNB 1606at signal flow 16-7. Downlink packets forwarded from the HeNB 1604 canbe sent to the UE 1602. Also, uplink packets can be sent from the UE1602, which are forwarded to the target Serving GW 1612 and on to thePDN GW 1614. Finally, the Target eNB 1606 sends a Handover Notify(TAI+ECGI) message to the MME 1608 at signal flow 16-8.

Explicit Deactivation of the LIPA PDN Connection after the Handover

In a second embodiment described with reference to the signal flowdiagram in FIG. 11 where the UE 1602 has a LIPA connection, the MME 1608performs the regular handover, but deactivates the LIPA PDN connectionby triggering an MME-initiated PDN disconnection with an indicationidentifying the LIPA PDN, where the indication may also provide aspecific reason/cause. The MME 1608 may do so during the handover orafter the handover is performed. If no specific cause is provided, theRel. 10+ UE detects that this is the LIPA connection and requests a newPDN for that APN, either automatically or based on policies. If aspecific cause is given, the UE reacts based on policies.

In operation, when the HeNB 1604 triggers the handover to a target cellby sending the handover request to the MME 1608 which includes theinformation on the target cell, the MME 1608 determines that there is anactive PDN connection that is a LIPA PDN connection based on the UEcontext information in the MME (including subscription information withLIPA indications, current CSG, current status of LIPA connections, etc.)and the information on the target cell (e.g. technology type, CSG ID).In addition, the MME 1608 determines that LIPA PDN continuity cannot besupported towards the target cell. To explicitly deactivate theconnection, the MME 1608 triggers the handover and, upon handovercompletion, the MME 1608 deactivates the LIPA PDN connections bytriggering an MME-initiated PDN disconnection. The MME 1608 may includea specific reason/cause for the de-activation.

Embodiments: Reject handoverIn accordance with selected embodiments,another solution is described with reference to FIG. 12, and addressesthe case of connected mode mobility from HeNB to macro E-UTRAN oranother HeNB for which LIPA continuity is not supported. In thissolution, instead of proceeding with HO procedure, the MME 1708 rejectsthe HO request from the first or source HeNB 1704, releases the PDNconnections, and sends a DETACH REQUEST message to UE 1702 based on theawareness that all the active PDN connections are connections for whichservice continuity is not provided and the information on the targetcell (e.g. technology type, CSG ID). As a result, the UE 1702 mayre-attach. With the solution, the MME 1708 is aware of the presence ofthe LIPA PDN connection when performing the handover.

The applied assumptions in this case are that (1) all the PDNconnections that UE has active are LIPA or SIPTO PDN connections. (2)Service Continuity for the LIPA is not supported, (3) UE is inECM-CONNECTED mode, (4) HO should be performed due to the UE's mobility,(5) Target cell belongs to a macro eNB or another HeNB that is notconnected to the residential/enterprise network (other CSG), and (6) MMErelocation is not involved.

In the disclosed embodiments, the release of LIPA/SIPTO PDN connectionsin case of handover is managed, but instead of proceeding with HOprocedure, the MME rejects the HO request from the source HeNB, releasesthe PDN connections, and sends a DETACH REQUEST message to the UE, allbased on the awareness that all the active PDN connections areconnections for which service continuity is not provided and theinformation on the target cell (e.g. technology type, CSG ID). As aresult, the UE may re-attach to the HeNB or the eNB. As will beappreciated, these solutions apply to the case where the MME receivesthe HO REQUIRED message from HeNB and discovers therefrom thatLIPA:SIPTO service continuity is not provided at the target cell (thatcan be GERAN/UTRAN) and the UE has only LIPA PDN connection(s). As thecause for the IRAT HO was UE's mobility, the UE may re-attach to a 2G/3Gnetwork as E-UTRAN may not be available.

Selected embodiments are described with reference to the signal flowdiagram in FIG. 12 where the UE 1702 has a LIPA/local SIPTO PDNconnection. When the HeNB 1704 triggers the handover to a target cell bysending the handover request to the MME 1708 which includes theinformation on the target cell, the MME 1708 determines that the activePDN connection are LIPA PDN connections based on the UE contextinformation in the MME. The MME 1708 determines that LIPA PDN continuitycannot be supported towards the target cell based on the UE contextinformation in the MME (including subscription information with LIPAindications, current CSG, current status of LIPA connections, etc.) andthe information on the target cell (e.g. technology type, CSG ID). Inaddition, the MME 1708 rejects the handover request and sends a DETACHREQUEST to the UE 1702 indicating “re-attach required.” Upon receivingthe DETACH REQUEST indicating “re-attach required,” the UE 1702 that isconnected to a HeNB 1702 and has at least one active PDN connection thatis a LIPA PDN connection determines whether the cell selected to performthe attach is the H(e)B that the UE was connected to when receiving theDETACH REQUEST. If the cell is not a HcNB (i.e., a CSG cell) or the cellbelongs to a different CSG, the UE determines, based on configurationinformation or operator policies or user policies, whether the PDNconnections that were active as LIPA PDN connections in the HeNB need tobe reactivated in the target cell upon or after the attach.

In the depicted signal flow 1700 shown in FIG. 12, the first or sourceHeNB 1704 sends Handover Required (Direct Forwarding Path Availability,Source to Target transparent container, target eNB Identity, target TAI.S1AP Cause) to the MME 1708 at signal flow 17-1. At signal flow 17-2,MME 1708 becomes aware that the active connections are PDN connectionsfor which continuity is not allowed towards the target cell and sends HOFailure message to eNB 1702. In addition, the MME 1708 initiates theLIPA PDN release procedure by sending DELETE SESSION REQUEST to the S-GW1710. At signal flow 17-3, the MME 1708 sends a DETACH REQUEST messageto the UE 1702 with detach type “re-attach required.” At signal flow17-3, the UE 1702 responds with a DETACH RESPONSE message to the MME1708. At signal flow 17-4, the UE 1702 send an ATTACH REQUEST message tothe MME 1708 after establishing RRC connection to the second or targeteNB 1706 through Random access procedure. The rest of the attachprocedure is performed thereafter.

Embodiments: Perform handover but omit LIPA PDN Connection informationlnaccordance with selected embodiments, another solution addresses thecase of connected mode mobility from HeNB to GERAN/UTRAN. In thissolution, the MME responds to the received HO REQUIRED message from HeNBby performing the handover as per current solutions. However, when theMME sends a Forward Relocation Request to the target SGSN, the MME omitsthe information regarding LIPA/SIPTO PDN connection(s) so that thetarget SGSN does not create a PDP context for the corresponding LIPA PDNconnection. In an example embodiment, if the source MME/SGSN has one ormore EPS PDN connection IEs regarding LIPA, and the source MME/SGSNlearns, based on operator configuration, that the target SGSN/MME is notaware of LIPA, the source MME/SGSN omits the EPS PDN connection IEregarding LIPA from the Forward Relocation Request message.

The applied assumptions in this case are that (1) UE has at least onePDN connection going through the core network and one or more LIPA PDNconnections, (2) Inter RAT HO occurs due to mobility, and (3) ServiceContinuity for the LIPA/SIPTO is not supported.

In this solution, when the MME receives the HO REQUIRED message fromHeNB, the MME is aware that LIPA/SIPTO service continuity is notsupported in the target (GERAN/UTRAN) cell based on the cell informationobtained from the HeNB and on the UE context information in the MME(including subscription information with LIPA indications, current CSG,current status of LIPA connections, etc.) and the information on thetarget cell (e.g. technology type, CSG ID). With this knowledge, the MMEperforms the handover as per current solutions, but when the MME sends aForward Relocation Request to the target SGSN, the MME omits theinformation regarding LIPA/SIPTO PDN connection(s), so that the targetSGSN does not create a PDP context for the corresponding LIPA PDNconnection. At the end of HO procedure, UE performs RAU with targetSGSN, which synchronizes the context information between the UE andSGSN. The source MME cleans up the LIPA/SIPTO PDN connection on L-GW(LS-GW and LP-GW).

In operation, the HeNB triggers the handover to a target cell and sendsthe handover request to the MME, including the information on the targetcell. In response, the MME determines that there is an active PDNconnection which is a LIPA PDN connection based on the UE contextinformation in the MME (including subscription information with LIPAindications, current CSG, current status of LIPA connections, etc.) andthe information on the target cell (e.g. technology type, CSG ID). Inaddition, the MME determines that LIPA PDN continuity cannot besupported towards the target cell based on the UE context information inthe MME (including subscription information with LIPA indications,current CSG, current status of LIPA connections, etc.) and theinformation on the target cell (e.g. technology type, CSG ID). As aresult, the MME omits the information regarding the LIPA PDN connectionsin the Forward Relocation Request sent to the target SGSN so that PDPContexts for such connections are not created. When the UE performshandover and the RAU and detects hat no PDP contexts have been createdin the target cell for the LIPA PDN connections, the UE determines(e.g., based on configuration information or operator policies or userpolicies) whether the PDN connection needs to be reactivated in thetarget cell.

Embodiments: Mobility between a HNB and GERAN/UTRAN or different CSGInaccordance with selected embodiments, another solution addresses thecase of connected mode mobility between a HNB and macro GERAN/UTRAN or adifferent CSG for which LIPA continuity is not provided. In thissolution, the SGSN determines during the handover preparation that theUE is moving to a cell for which LIPA continuity cannot be provided, andupon completion of the handover, the SGSN initiates PDP contextdeactivation procedure for LIPA/SIPTO PDP context(s) possibly providingan explicit cause indicating that the deactivation is due to LIPAcontinuity not being supported.

The applied assumptions in this case are that (1) LIPA/SIPTO servicecontinuity is not supported, (2) UE has at least one LIPA/SIPTO PDPcontext, and (3) UE is in CONNECTED mode. Also, in 2G/3G networks, it isunderstood that releasing a Radio Access Bearer (RAB) does not mean thatthe corresponding PDP context is released.

In this solution, if the handover does not include a change of SGSN,then the handover is performed regularly. In addition, the SGSNdetermines during the handover preparation that the UE is moving to acell for which LIPA continuity cannot be provided, and upon completionof the handover, the SGSN initiates PDP context deactivation procedurefor LIPA/SIPTO PDP context(s) possibly providing an explicit causeindicating that the deactivation is due to LIPA continuity not beingsupported.

On the other hand, if the handover involves a change of SGSN and thetarget SGSN is LIPA-aware, then the source SGSN provides the completeuser context to the target SGSN. In addition, the source or target SGSNdetermines that the UE is moving to a cell for which LIPA continuitycannot be provided, and upon completion of the handover, the target SGSNinitiates PDP context deactivation procedure for LIPA/SIPTO PDPcontext(s), possibly providing an explicit cause indicating that thedeactivation is due to LIPA continuity not being supported in order forthe UE to not try again.

In operation, the EPS bearer context deactivation is initiated by theMME/network. In particular, if a NAS signaling connection exists whenthe MME initiates the EPS bearer context deactivation procedure, the MMEinitiates the EPS bearer context deactivation procedure by sending aDEACTIVATE EPS BEARER CONTEXT REQUEST message to the UE and enters thestate BEARER CONTEXT INACTIVE PENDING. The DEACTIVATE EPS BEARER CONTEXTREQUEST message contains an ESM cause typically indicating one of thefollowing causes: (1) operator determined barring, (2) regulardeactivation. (3) network failure, (4) reactivation requested, (5) APNrestriction value incompatible with active EPS bearer context, or (6)LIPA connectivity is not supported in the current cell. This last EMMcause is sent to the UE if MME detects that the UE handed over towards acell which does not support LIPA. If the deactivation is triggered by aUE initiated bearer resource modification procedure or UE requested PDNdisconnect procedure, the DEACTIVATE EPS BEARER CONTEXT REQUEST messagecontains the procedure transaction identity (PTI) value received by theMME in the BEARER RESOURCE MODIFICATION REQUEST or PDN DISCONNECTREQUEST respectively. If the UE receives the DEACTIVATE EPS BEARERCONTEXT REQUEST which includes ESM cause “LIPA connectivity is notsupported in the current cell,” the UE does not try to reactivate theEPS bearer context for that LIPA APN until it moves to another cell, anddoes not try to activate any other EPS bearer context for a LIPA APN.

In this case, it will be appreciated that pre-Rel. 10 UEs are notconfigured to understand when a cause is provided to indicate that thedeactivation is due to LIPA continuity not being supported. Also,pre-Rel. 9 UEs will establish the PDP context again.

Embodiments: Idle mode mobility In accordance with selected embodiments,another solution addresses the cases of idle mode mobility from a HeNBto a eNB or to a HeNB in a different CSG, and mobility from a HNB tomacro coverage or to a HNB in a different CSG. This solution uses theUE's Access Stratum (AS)—also known at the NAS layer as lower layer—todetect if the UE has left a specific CSG coverage, including the UEleaving a cell with a CSG ID, and informs the NAS of such event. Inresponse, the NAS can take a variety of actions described below withreference to managing the release of a LIPA PDN connection. If the UEhas at least one PDN connection that is not a LIPA PDN connection andthe UE has received an indication from the lower layers that the UE hasmoved to a target CSG cell and the UE determines that the target CSGcell has a CSG identity that is different from the CSG identity of theprevious cell, or an indication from the lower layers that the UE hasmoved to a cell that is not a CSG cell or does not have a CSG ID, the UEsends a Tracking Area Update request or a PDN Disconnect Request foreach LIPA PDN connection if the UE is camping or connected to E-UTRAN,or sends a Routing Area Update request or a PDP context disconnectionrequest for each LIPA PDP context or LIPA PDN connection if the UE iscamping or connected to GERAN or UTRAN. In this solution, the UEperforms a Tracking Area Update procedure or a Combined Tracking AreaUpdate procedure to synchronize the UE EPS bearer context with the MMEEPS bearer context for UE mobility where the source cell is a CSG celland the target cell is not a CSG cell, when the UE has at least one LIPAPDN connection. By performing a Tracking Area Update procedure or aCombined Tracking Area Update procedure, the UE synchronizes the UE EPSbearer context with the MME EPS bearer context for UE mobility where thesource cell is a CSG cell and the target cell is a CSG cell, and wherethe target cell's CSG-ID is not the source cell's CSG-ID, when the UEhas at least one LIPA PDN connection. In this solution, the UE performsa Routing Area Update procedure to synchronize the UE context with theSGSN context in for UE mobility where the source cell is a CSG cell andthe target cell is not a CSG cell, when the UE has at least one LIPA PDNconnection. As will be appreciated, the solution does not work withpre-Rel. 10 UEs.

In selected embodiments, the UE determines that LIPA continuity isallowed or not allowed in a target cell based on the CSG ID of thesource cell and the target cell being a non-CSG cell or not having a CSGID.

Access Stratum Notification

For example, in an access stratum notification embodiment, an NAS idleUE moves outside the H(e)NB, at which point the AS in the UE makes theNAS in the UE aware of the fact the UE has moved outside the previousH(e)NB. Such AS notification can occur when the UE has moved to macrocoverage—either E-UTRAN or GERAN/UTRAN—or to a different CSG or to acell with a different CSG ID. In response to the AS notification, the UENAS triggers appropriate NAS signaling, such as a TAU or LIPA/SIPTO PDNdisconnection procedure for E-UTRAN, or RAU or PDP context disconnectionin UTRAN.

In selected embodiments, the UE in state EMM-REGISTERED initiates thetracking area updating procedure by sending a TRACKING AREA UPDATEREQUEST message to the MME when the UE has at least one LIPA PDNconnection and the UE has received an indication from the lower layersthat the UE has moved to a target CSG cell and the UE determines thatthe target CSG cell has a CSG identity that is different from the CSGidentity of the previous cell, or an indication from the lower layersthat the UE has moved to a cell that is not a CSG cell. If the MMEreceives a TRACKING AREA UPDATE REQUEST from a UE in a cell that is nota CSG cell, and the MME determines that the UE has only LIPA PDNconnections, then the MME rejects the tracking area updating procedure.In selected embodiments, the MME sends a TRACKING AREA UPDATE REJECT andindicate “Implicitly Detached” or “No EPS Bearer Context Activated” ifthe MME received the TRACKING AREA UPDATE REQUEST from a UE in a cellthat is not a CSG cell and the MME determines that the UE has only LIPAPDN connections. In response, the UE deletes the list of equivalentPLMNs and deactivate all the EPS bearer contexts locally, if any, andenters the state EMM-DEREGISTERED.NORMAL-SERVICE. The UE then performs anew attach procedure. As will be appreciated, the conditions describedabove are equivalent to the conditions in which the UE receives anindication from the lower layers that the UE has performed a handoverfrom a CSG cell to a target cell with a different CSG identity, or to acell that is not a CSG cell.

In other embodiments, the UE operating in CS/PS mode 1 or CS/PS mode 2,in state EMM-REGISTERED, initiates the combined tracking area updatingprocedure when the UE has at least one LIPA PDN connection and the UEhas received an indication from the lower layers that the UE has movedto a target CSG cell and the UE determines that the target CSG cell hasa CSG identity that is different from the CSG identity of the previouscell, or an indication from the lower layers that the UE has moved to acell that is not a CSG cell.

In another embodiment, in order to request PDN disconnection from a PDN,the UE sends a PDN DISCONNECT REQUEST message to the MME. If the UE hasat least one PDN connection that is not a LIPA PDN connection and the UEhas received an indication from the lower layers that the UE has movedto a target CSG cell and the UE determines that the target CSG cell hasa CSG identity that is different from the CSG identity of the previouscell, or an indication from the lower layers that the UE has moved to acell that is not a CSG cell, the UE sends a PDN Disconnect Request foreach LIPA PDN connection.

The UE NAS issues appropriate signaling if the UE is moving from a HeNBto E-UTRAN/UTRAN/GERAN macro coverage, or from a HNB to UTRAN/GERANmacro coverage, or from a H(e)NB in a CSG to an H(e)B in another CSG,based on the CSG ID of the new cell or based on the new cell being anon-CSG cell or not having a CSG ID. In this embodiment, the NASsignaling can be (1) a TAU procedure, (2) a PDN disconnection procedureif the UE has at least two PDN connections and at least one PDNconnection is a LIPA PDN connection, or (3) a detach procedure if the UEhas only LIPA PDN connections followed by an attach procedure. With thisapproach, the UE becomes aware as soon as leaving the H(e)NB that theLIPA connectivity is lost.

AS Notification with Idle Timer

In an AS notification with idle timer embodiment, when the UE entersEMM-IDLE mode, the UE NAS starts a timer LIPA_IDLE_MODE (a.k.a. theLIPA_CONNECTIVITY timer). The UE NAS and also stores the identity of thecurrent CSG cell when entering NAS idle mode in the H(e)NB if the UE hasat least one active LIPA connection. The AS in the UE notifies the NASin the UE that the UE has moved outside the previous H(e)NB (e.g., whenthe UE moves to macro coverage—either E-UTRAN or GERAN/UTRAN—or to adifferent CSG).

If the NAS is notified by the AS before the LIPA_IDLE_MODE timer hasexpired, the UE stores the notification from the AS and does not performany NAS signaling at that time. However, upon timer expiration, the NASperforms either a TAU or LIPA/SIPTO PDN disconnection procedure forE-UTRAN, or RAU/PDP context disconnection in UTRAN if the UE is movingfrom a HeNB to E-UTRAN/UTRAN/GERAN macro coverage, or from a HNB toUTRAN/GERAN macro coverage, or from a H(e)NB in a CSG to an H(e)B inanother CSG, based on the CSG ID of the new cell.

In selected embodiments, the UE in state EMM-REGISTERED initiates thetracking area updating procedure by sending a TRACKING AREA UPDATEREQUEST message to the MME when the timer LIPA_CONNECTIVITY timerexpires and the UE has received an indication from the lower layers thatthe UE has moved to a target CSG cell and the UE determines that thetarget CSG cell has a CSG identity that is different from the CSGidentity stored when the UE entered the EMM-IDLE mode, or to a cell thatis not a CSG cell. If the MME receives a TRACKING AREA UPDATE REQUESTfrom a UE in a cell that is not a CSG cell, and the MME determines thatthe UE has only LIPA PDN connections, then the MME rejects the trackingarea updating procedure. In selected embodiments, the MME sends aTRACKING AREA UPDATE REJECT and indicate “Implicitly Detached” or “NoEPS Bearer Context Activated” if the MME received the TRACKING AREAUPDATE REQUEST from a UE in a cell that is not a CSG cell and the MMEdetermines that the UE has only LIPA PDN connections. In response, theUE deletes the list of equivalent PLMNs and deactivate all the EPSbearer contexts locally, if any, and enters the stateEMM-DEREGISTERED.NORMAL-SERVICE.

In other embodiments, the UE operating in CS/PS mode 1 or CS/PS mode 2,in state EMM-REGISTERED, initiates the combined tracking area updatingprocedure when the LIPA_CONNECTIVITY timer expires and the UE hasreceived an indication from the lower layers that the UE has moved to atarget CSG cell and the UE determines that the target CSG cell with hasa CSG identity that is different from the CSG identity stored when theUE entered the EMM-IDLE mode, or to a cell that is not a CSG cell.

In other embodiments, in order to request PDN disconnection from a PDN,the UE sends a PDN DISCONNECT REQUEST message to the MME which includesthe EPS bearer identity of the default bearer associated with the PDN todisconnect from as the linked EPS bearer identity in the PDN DISCONNECTREQUEST message. If the UE has at least one LIPA PDN connection and theUE has received an indication from the lower layers that the UE hasmoved to a target CSG cell and the UE determines that the target CSGcell has a CSG identity that is different from the CSG identity of theprevious cell, or an indication from the lower layers that the UE hasmoved to a cell that is not a CSG cell and the timer LIPA_CONNECTIVITYhas expired, the UE shall send a PDN Disconnect Request for each LIPAPDN connection.

On the other hand, if the NAS is notified by the AS after theLIPA_IDLE_MODE timer has expired, the NAS triggers appropriate NASsignaling (either a TAU or LIPA/SIPTO PDN disconnection procedure forE-UTRAN, or RAU/PDP context disconnection in UTRAN) if the UE is movingfrom a HeNB to E-UTRAN/UTRAN/GERAN macro coverage, or from a HNB toUTRAN/GERAN macro coverage, or froma H(e)NB in a CSG to an H(e)B inanother CSG, based on the CSG ID of the new cell. In this embodiment,the NAS signaling can be (1) a TAU procedure, (2) a PDN disconnectionprocedure if the UE has at least two PDN connections and at least onePDN connection is a LIPA PDN connection, or (3) a detach procedure ifthe UE has only LIPA PDN connections followed by an attach procedure.

AS Notification with Out-Of-Coverage Timer

In an AS notification with out-of-coverage timer embodiment, the UE ASnotifies the UE NAS when the UE has moved outside the previous H(e)NB(e.g., when the UE moves to macro coverage—either E-UTRAN orGERAN/UTRAN—or to a different CSG) by providing an indication to theupper layers. The notified UE NAS stores the CSG ID of the previousH(e)NB and starts a new timer LIPA OUT OF COVERAGE. If the UE moves toan H(e)NB, the UE AS notifies the UE NAS that the UE has moved to thecoverage of the new H(e)NB and provides the CSG ID of the target H(e)NBto the UE NAS. If the CSG ID is the same as the one stored by the UE NASand the indication reaches the UE NAS before the LIPA OUT OF COVERAGEtimer expires, the UE NAS resets the LIPA OUT OF COVERAGE timer.However, if the LIPA OUT OF COVERAGE timer expires, the NAS triggersappropriate NAS signaling (either a TAU or LIPA/SIPTO PDN disconnectionprocedure for E-UTRAN, or RAU/PDP context disconnection in UTRAN). Inthis embodiment, the NAS signaling can be (1) a TAU procedure, (2) A PDNdisconnection procedure if the UE has at least two PDN connections andat least one PDN connection is a LIPA PDN connection, or (3) a detachprocedure if the UE has only LIPA PDN connections followed by an attachprocedure.

Embodiments: Delay in UE discovery of lost connectivityIn accordancewith selected embodiments, another solution addresses the cases of idlemode mobility, and delay in UE discovery of lost connectivity due toidle mode mobility between H(e)NB and macro coverage or other H(e)NB forwhich continuity shall not be provided. In this solution, when the UEreceives SGSN/MME paging and the UE replies to the paging from a cellfor which LIPA continuity is not supported, the SGSN/MME releases theLIPA PDN connections. This may result in the UE being detached if theLIPA PDN connection(s) being disconnected by the MME are the only PDNconnections active.

In operation, a UE is paged by the SGSN or MME. If the UE replies to thepaging from a cell for which LIPA continuity is not supported, theSGSN/MME releases the LIPA PDN connections. The SGSN/MME determines thatLIPA continuity is not supported based on the information of the cellthe UE is answering the paging from (e.g. RAT type, CSG ID) and the UEcontext in the SGSN/MME. This may result in the UE being detached if theLIPA PDN connection(s) being disconnected by the MME are the only PDNconnections active. In selected embodiments, the SGSN/MME disconnectsthe LIPA connections only if the downlink data that triggered the pagingcorresponds to (one of) the LIPA PDN connections. In other embodiments,the SGSN/MME disconnects the LIPA connections independently of what PDNconnection the downlink belongs to based on the fact that the UEresponds to the paging from a cell for which LIPA PDN connectioncontinuity shall not be supported.

Embodiments: Connected mode mobilityln accordance with selectedembodiments, another solution addresses the cases of connected modemobility from HeNB to GERAN/UTRAN with ISR active, and from HNB toGERAN/UTRAN. The solution uses the Access Stratum (AS) of the UE todetect if the UE has left a specific CSG coverage before the UE performsany NAS signaling, and informs the NAS of such event. In response, theNAS can take a variety of actions described below with reference tomanaging the release of a LIPA PDN connection. This could includedeactivation of ISR in certain scenarios.

In selected embodiments, the UE determines that LIPA continuity isprovided or not provided in a target cell based on the CSG ID of thesource cell being different from the CSG ID of the target cell, or thetarget cell being a non-CSG cell or not having a CSG ID, or the UEmoving to a different CSG cell with the same CSG ID of the source cell.

UE-Based for HNB to Macro GERAN/UTRAN, ISR-Enabled

In a UE-based embodiment for HNB to macro GERAN/UTRAN, ISR-enabled, theIdle mode Signaling Reduction (ISR) is enabled when LIPA PDN connectionsare present to address the cases of connected mode mobility from HeNBsource cell to a GERAN/UTRAN target cell, and the case of CS Fallbackwith PS HO. To this end, the solution takes advantage of the fact thatthe AS and NAS in the UE know that there is an intersystem change (i.e.,that the UE has performed a handover between a source cell of a firstradio technology to a target cell of a different type of technology).

In operation, the AS in a UE makes the UE NAS aware of the inter-systemchange. If the UE determines that LIPA continuity is allowed, the UEdoes not do anything. However, if the UE determines that LIPA continuityis not allowed (or does not know whether LIPA continuity is allowed) andthat at least one of the PDN connections active in the HeNB before thehandover is a LIPA connection, then the UE triggers appropriate NASsignaling (either a TAU or LIPA/SIPTO PDN disconnection procedure forE-UTRAN, or RAU/PDP context disconnection in UTRAN).

In selected embodiments, the UE in state EMM-REGISTERED initiates thetracking area updating procedure by sending a TRACKING AREA UPDATEREQUEST message to the MME when the UE has at least one LIPA PDNconnection and the UE has received an indication from the lower layersthat the UE has moved to a target CSG cell and the UE determines thatthe target CSG cell has a CSG identity that is different from the CSGidentity of the previous cell, or an indication from the lower layersthat the UE has moved to a cell that is not a CSG cell. However, if theMME receives a TRACKING AREA UPDATE REQUEST from a UE in a cell that isnot a CSG cell, and the MME determines that the UE has only LIPA PDNconnections, then the MME shall reject the tracking area updatingprocedure. In selected embodiments, the MME sends a TRACKING AREA UPDATEREJECT and indicate “Implicitly Detached” or “No EPS Bearer ContextActivated” if the MME received the TRACKING AREA UPDATE REQUEST from aUE in a cell that is not a CSG cell and the MME determines that the UEhas only LIPA PDN connections. In response, the UE shall delete the listof equivalent PLMNs and deactivate all the EPS bearer contexts locally,if any, and shall enter the state EMM-DEREGISTERED.NORMAL-SERVICE.

In other embodiments, the UE operating in CS/PS mode 1 or CS/PS mode 2,in state EMM-REGISTERED, shall initiate the combined tracking areaupdating procedure when the UE has at least one LIPA PDN connection andthe UE has received an indication from the lower layers that the UE hasmoved to a target CSG cell and the UE determines that the target CSGcell has a CSG identity that is different from the CSG identity of theprevious cell, or an indication from the lower layers that the UE hasmoved to a cell that is not a CSG cell.

The UE may establish one or more PDP contexts corresponding to the oneor more APNs corresponding to the one or more LIPA PDN connections basedon configuration information or operator policies or user policies.

UE-Based for HNB to Macro GERAN/UTRAN with Delayed Disconnection,ISR-Enabled

In a UE-based embodiment for HNB to macro GERAN/UTRAN with delayeddisconnection, ISR-enabled, a timer is added to address the problem ofhysteresis and delay in disconnecting the LIPA connection. In operation,the AS in the UE notifies the UE NAS of an inter-system change. Oncenotified, the NAS stores the CSG ID of the HeNB. If at least one of thePDN connections active in the HeNB before the handover is a LIPAconnection, then the UE NAS starts a new timer LIPA_ACTIVE_MODE if itreceives indication from the lower layers that the UE has performed ahandover from a CSG cell to a target cell with a different CSG identity,or to a cell that is not a CSG cell. If there is no traffic to betransmitted over the LIPA PDN connections, the UE does not deactivatethe LIPA PDP contexts, even if LIPA PDN connectivity is not supported inthe current cell. If the LIPA-ACTIVE_MODE timer is active or running andthe UE has traffic to be transmitted over one of the LIPA PDN contexts,then the UE triggers appropriate NAS signaling (either a TAU orLIPA/SIPTO PDN disconnection procedure for E-UTRAN, or RAU/PDP contextdisconnection in UTRAN).

In other embodiments, the UE starts a timer LIPA_Connectivity if itreceives indication from the lower layers that the UE has performed ahandover from a CSG cell to a target cell with a different CSG identity,or to a cell that is not a CSG cell.

In selected embodiments, the UE in state EMM-REGISTERED initiates thetracking area updating procedure by sending a TRACKING AREA UPDATEREQUEST message to the MME when the timer LIPA_CONNECTIVITY timer isrunning or has not expired and the UE has received an indication fromthe lower layers that the UE has moved to a target CSG cell and the UEdetermines that the target CSG cell has a CSG identity that is differentfrom the CSG identity of the previous cell, or an indication from thelower layers that the UE has moved to a cell that is not a CSG cell, andthe UE has uplink user data to send over a LIPA PDN connection. However,if the MME receives a TRACKING AREA UPDATE REQUEST from a UE in a cellthat is not a CSG cell, and the MME determines that the UE has only LIPAPDN connections, then the MME shall reject the tracking area updatingprocedure. In selected embodiments, the MME sends a TRACKING AREA UPDATEREJECT and indicate “Implicitly Detached” or “No EPS Bearer ContextActivated” if the MME received the TRACKING AREA UPDATE REQUEST from aUE in a cell that is not a CSG cell and the MME determines that the UEhas only LIPA PDN connections. In response, the UE shall delete the listof equivalent PLMNs and deactivate all the EPS bearer contexts locally,if any, and shall enter the state EMM-DEREGISTERED.NORMAL-SERVICE.

In other embodiments, the UE operating in CS/PS mode 1 or CS/PS mode 2,in state EMM-REGISTERED, shall initiate the combined tracking areaupdating procedure when the timer LIPA_CONNECTIVITY timer is running orhas not expired or the timer LIPA-ACTIVE_MODE is running or has notexpired and the UE has received an indication from the lower layers thatthe UE has moved to a target CSG cell and the UE determines that thetarget CSG cell has a CSG identity that is different from the CSGidentity of the previous cell, or an indication from the lower layersthat the UE has moved to a cell that is not a CSG cell, and the UE hasuplink user data to send over a LIPA PDN connection.

In other embodiments, in order to request PDN disconnection from a PDN,the UE shall send a PDN DISCONNECT REQUEST message to the MME whichincludes the EPS bearer identity of the default bearer associated withthe PDN to disconnect from as the linked EPS bearer identity in the PDNDISCONNECT REQUEST message. If the UE has at least one LIPA PDNconnection and the UE has received an indication from the lower layersthat the UE has moved to a target CSG cell and the UE determines thatthe target CSG cell has a CSG identity that is different from the CSGidentity of the previous cell, or an indication from the lower layersthat the UE has moved to a cell that is not a CSG cell and the timerLIPA_CONNECTIVITY has expired or the timer LIPA-ACTIVE_MODE has expired,and the UE has uplink user data to send over a LIPA PDN connection, theUE shall send a PDN Disconnect Request for each LIPA PDN connection.

When the LIPA_ACTIVE_MODE timer expires or the LIPA_CONNECTIVITY timerexpires, the UE does nothing if the UE is connected to a HeNB or HNBwith a CSG ID that matches the stored CSG ID. However, if the UE isconnected to a HeNB with a CSG ID different than the stored CSG ID whenthe LIPA_ACTIVE_MODE timer expires or the LIPA_CONNECTIVITY timerexpires, then the UE does not do anything if the UE determines that LIPAcontinuity is allowed. Conversely, if the LIPA_ACTIVE_MODE timer expiresor the LIPA_CONNECTIVITY timer expires and the UE determines that LIPAcontinuity is not allowed or the UE does not know whether LIPAcontinuity is allowed, then the UE triggers appropriate NAS signaling(either a TAU or LIPA/SIPTO PDN disconnection procedure for E-UTRAN, orRAU/PDP context disconnection in UTRAN). The UE may establish one ormore PDP contexts corresponding to the one or more APNs corresponding tothe one or more LIPA PDN connections based on configuration informationor operator policies or user policies.

Upon receipt of the HANDOVER COMMAND message, the UE initiates therelease of link layer connections, disconnects the physical channels(including the packet resources, if in class A mode of operation),commands the switching to the assigned channels, and initiates theestablishment of lower layer connections (this includes the activationof the channels, their connection and the establishment of the datalinks). The UE also provides an indication to the upper layer if thehandover is from a CSG cell to another CSG cell or from a CSG cell to acell that is not a CSG cell. If the target cell is a CSG cell, themobile station shall provide to the upper layer the CSG ID of the targetcell. Alternatively, if the current cell is a CSG cell, the UE providesan indication to the upper layer, and if the target cell is a CSG cell,the mobile station shall provide to the upper layer the CSG ID of thetarget cell. Alternatively, if the source cell is a CSG cell, the UEprovides an indication to the upper layer, and if the target cell is aCSG cell, the UE provides to the upper layer the CSG ID of the targetcell.

UE-Based for HNB to Macro GERAN/UTRAN

In a UE-based embodiment for HNB to macro GERAN/UTRAN, Idle modeSignaling Reduction (ISR) is enabled when LIPA PDN connections arepresent to address the cases of active mode mobility from HeNB to aGERAN/UTRAN macro coverage. In operation, the AS in the UE makes the UENAS aware of the change from a CSG cell to macro coverage. If the UEdetermines that at least one of the PDP contexts active when connectedover the HNB is a LIPA connection and that LIPA continuity is allowed,the UE does not do anything. However, if the UE determines that at leastone of the PDP contexts active when connected over the HNB is a LIPAconnection and that LIPA continuity is not allowed (or the UE does notknow whether LIPA continuity is allowed), then the UE triggersappropriate NAS signaling (either a TAU or LIPA/SIPTO PDN disconnectionprocedure for E-UTRAN, or RAU/PDP context disconnection in UTRAN) anddisconnects the corresponding PDP contexts. The UE may reconnect the PDPcontext to the APN corresponding to the LIPA PDN connection based onconfiguration information or operator policies or user policies

UE-Based for HNB to Macro GERAN/UTRAN with Delayed Disconnection

In a UE-based embodiment for HNB to macro GERAN/UTRAN with delayeddisconnection, a timer is added to address the problems of hysteresisand delay in disconnecting the LIPA connection. In operation, the AS inthe UE makes the UE NAS aware of the change from a CSG cell to macrocoverage. In response, the NAS stores the CSG ID of the HNB. If at leastone of the PDP contexts active in the HNB before the handover is a LIPAconnection, then the UE NAS starts a new timer LIPA_ACTIVE_MODE and doesnot deactivate any PDP contexts even if LIPA PDN connectivity is notsupported in the current cell. When the LIPA_ACTIVE_MODE timer expiresand the UE is connected to a HNB with a CSG ID that matches the storedCSG ID, then the UE does nothing. However, if the UE is connected to aHNB with a CSG ID different than the stored CSG ID when theLIPA_ACTIVE_MODE timer expires and the UE determines that LIPAcontinuity is allowed, then the UE does not do anything. Alternatively,if the UE is connected to a HNB with a CSG ID different than the storedCSG ID when the LIPA_ACTIVE_MODE timer expires and the UE determinesthat LIPA continuity is not allowed (does not know whether LIPAcontinuity is allowed), then the UE disconnects the corresponding PDPcontexts. The UE may reconnect the PDP context to the APN correspondingto the LIPA PDN connection based on configuration information oroperator policies or user policies.

Deactivation of ISR

In an ISR deactivation embodiment, the case of idle mode mobilitybetween a HeNB and an eNB, mobility between a HNB and macro GERAN/UTRAN,and mobility between HeNBs (respectively HNBs) belonging to differentCSGs and for which LIPA continuity shall not be provided is addressed byensuring that ISR is not enabled in the presence of LIPA connectivity.In operation, a UE that attaches to E-UTRAN in a HeNB/CSG cell and thatis connected with a LIPA PDN connection shall locally deactivate ISR.Similarly, if a UE is attached to E-UTRAN and activates a LIPA PDNconnection while connected to a HeNB, the UE shall locally deactivateISR. Finally, if the MME serves a UE attached to E-UTRAN in a HeNB/CSGcell, and the MME receives a request for a LIPA PDN connection or for aPDN connection to be subjected to SIPTO, then the MME shall not indicateto the UE that ISR is to be activated.

Embodiments: MME releases LIPA/SIPTO PDN connections before sendingInitial Context Setup Request messageIn accordance with selectedembodiments, another solution is described with reference to FIG. 13,and addresses the case of NAS idle mode mobility where the UE enters NASconnected mode after performing idle mobility outside the H(e)NB. Inthis solution, if a UE 1802 sends a Service Request (SR) to the MME 1806from a cell for which LIPA/SIPTO service continuity is not provided fora LIPA PDN connection previously established in a HeNB, the MME 1806releases LIPA/SIPTO PDN connections before sending an Initial ContextSetup Request message to the target eNB 1804.

The applied assumptions in this case are that (1) the UE had a PDNconnection that goes through the core network as well as LIPA PDNconnection before it enters into IDLE mode, (2) Service Continuity forthe LIPA and SIPTO local is not supported, (3) the UE is in ECM-IDLEmode before the UE sends SERVICE REQUEST, and (4) MME relocation is notinvolved.

In operation, a UE 1802 sends a Service Request (signal flow 18-1) tothe MME 1806 from a cell which does not provide LIPA/SIPTO servicecontinuity for a previously established LIPA PDN connection in a HeNB.Upon receiving SR from the UE 1802, MME 1806 discovers that the UE 1802is connected to a cell to which LIPA/SIPTO service continuity is notprovided. Before the MME 1806 sends an Initial Context Setup Requestmessage to the target eNB 1804 (signal flow 18-3), the service requestis treated at the MME 1806 (signal flow 18-2) by providing bearers forall the EPS bearers excluding the LIPA bearers if there are PDNconnections that are not LIPA PDN connections. The rest of procedure(signal flows 18-4 through 18-9) follows UE-initiated Service Requestprocedures.

Embodiments: MME sends SERVICE REJECT message with cause indicatorInaccordance with selected embodiments, another solution is described withreference to FIG. 14, and addresses the case of NAS idle mode mobilitywhere the UE enters NAS connected mode after performing idle mobilityoutside the HeNB. In this solution, if a UE 1902 sends a Service Request(SR) to the MME 1906 from a cell for which LIPA/SIPTO service continuityis not provided for a LIPA PDN connection previously established in afirst or source HeNB 1904, and the UE 1902 has only LIPA PDNconnections, then the MME 1908 sends SERVICE REJECT message whichspecifies an “Implicitly Detached” cause (since releasing LIPA PDNconnection results in UE being detached from the network).

The applied assumptions in this case are that (1) the UE had only LIPAPDN connections before it enters into IDLE mode. (2) Service Continuityfor the LIPA and SIPTO local is not supported, (3) the UE is in ECM-IDLEmode before the UE sends SERVICE REQUEST, and (4) MME relocation is notinvolved.

In operation, a UE 1902 sends a Service Request to the MME 1908 (signalflow 19-1) from a cell for which LIPA/SIPTO service continuity is notprovided for a LIPA PDN connection previously established in a HeNB.Upon receiving the SR from the UE 1902, MME 1908 discovers that the UEis connected to a cell which is not directly connected to theresidential/enterprise network. Based on this, the MME sends SERVICEREJECT message (signal flow 19-2) with a specified cause “ImplicitlyDetached” (since releasing LIPA PDN connection results in UE beingdetached from the network). In response, the UE 1902 releases all thebearer contexts and resets its EMM status to EMM-DETACHED and re-attachto the network by sending out ATTACH REQUEST to the MME 1908 (signalflow 19-4). The UE 1902 may or may not attempt to reconnect to the APNscorresponding to the previous LIPA PDN connections by requesting forLIPA connectivity for such APNs.

Alternatively, the MME 1908 can send a new reject cause “implicitlydetached—LIPA not allowed.” In response, the UE 1902 releases all thebearer contexts, resets its EMM status to EMM-DETACHED, and re-attachesto the network by sending out an ATTACH REQUEST message to the MME 1908after establishing RRC connection 19-3 to the second or target eNB 1906.The UE 1902 will not try to reconnect to the APNs corresponding to theprevious LIPA PDN connections by requesting for LIPA connectivity forsuch APNs.

Embodiments: LIPA PDN Connection establishmentin accordance withselected embodiments, another solution is described with reference toFIG. 15, and addresses the case of NAS idle mode mobility where the UEenters NAS connected mode after performing idle mobility outside theHeNB. In this solution, a LIPA PDN connection is a PDN Connection thatthe MME authorizes for connectivity to a PDN GW for a UE connected to aHeNB based on a request from the UE for LIPA connectivity and based onthe CSG ID of the HeNB. Alternatively, a LIPA PDN Connection is a PDNConnection which was activated by the UE requesting LIPA connectivitytype “LIPA” and the MME informing the UE of the connectivity typeprovided. Alternatively, a LIPA PDN Connection is a PDN Connection orPDP Context that gives access to the UE to services located in the localresidential/corporate IP network.

In this solution, if a UE 2002 sends a Service Request to the MME 2008from a cell for which LIPA/SIPTO service continuity is not provided fora LIPA PDN connection previously established in a HeNB, and the UE 2002has only LIPA PDN connections, then the MME 2008 orders the UE 2002 toinitiate another PDN connection by sending a NEW PDN CONNECTION REQUESTmessage. This is based on the idea of introducing a new NAS message.Thus, if the network/MME receives a SERVICE REQUEST from a UE in a cellthat is not a CSG cell or a CSG cell with a CSG identity different fromthe CSG identity of the cell where the UE activated the LIPA PDNconnection, then the network/MME returns a SERVICE REJECT message.Alternatively, if the network receives a SERVICE REQUEST from a UE in acell that is not a CSG cell or a CSG cell with a CSG identity differentfrom the CSG identity of the cell where the MME received the ACTIVATEPDP CONTEXT REQUEST from the UE for the LIPA PDP contexts, then thenetwork returns a SERVICE REJECT message.

The applied assumptions in this case are that (1) the UE had only LIPAPDN connections before it enters into IDLE mode, (2) Service Continuityfor the LIPA and SIPTO local is not supported, (3) UE is in ECM-IDLEmode before the UE sends SERVICE REQUEST, and (4) MME relocation is notinvolved.

In operation, a UE 2002 sends a Service Request to the MME 2008 (signalflow 20-1), either on arrival of UL packet or as a response to a pagingmessage. At signal flow 20-2, the MME 2008 sends either a NEW PDNCONNECTION REQUEST message to the UE 2002 (this message implies that theexisting PDN connection, which is LIPA PDN connection, is not availableto use), or a SERVICE REJECT message with a new cause “New PDNconnection is required.” (It will be noted that the NEW PDN CONNECTIONREQUEST message has not been defined, so this solution does not workwith pre-Rel. 10 UEs.) At signal flow 20-3, the UE 2002 responds to themessage by locally releasing the existing LIPA PDN connections andinitiating a PDN connection establishment procedure by sending a PDNConnectivity Request to MME (signal flow 20-3). If all the active PDPcontexts are LIPA PDP contexts, then the UE may use an APN in the attachprocedure that is different from the APNs corresponding to the activeLIPA PDP contexts. For the new PDN connection, APN will be selectedbased on the UE's local policy.

When sending the NEW PDN CONNECTION REQUEST message, the MME 2008 canuse a notification procedure to inform the UE 2002 about events whichare relevant for the upper layer which is using an EPS bearer context orhas requested a procedure transaction. If the UE 2002 indicates that itsupports the notification procedure, the network may initiate theprocedure at any time while a PDN connection exists or a proceduretransaction is ongoing. For example, MME 2008 can initiate thenotification procedure by sending a NOTIFICATION message to the UE 2002.When the UE 2002 receives the NOTIFICATION message, the ESM protocolentity in the UE 2002 provides the notification indicator to the upperlayer having one of two values. The first value can be used to signifythat a handover is cancelled and that session re-establishment beperformed. The second value can be used to signify that no active PDNconnection is available and that a PDN connection needs to bere-established.

In selected embodiments, the MME sends a SERVICE REJECT message andindicates that a new PDN connection is needed if the MME received aSERVICE REQUEST from a UE in cell that is not a CSG cell and the UE hasat east one LIPA PDN connection. In other embodiments, the MME sends aSERVICE REJECT message and indicates that a new PDN connection is neededif the MME received a SERVICE REQUEST from a UE in a CSG cell with a CSGidentity different from the CSG identity of the cell where the UEactivated the PDN connection or PDN connections. In response, the UEperforms a UE-requested PDN connectivity procedure. In the case of a UEthat has only LIPA PDN connections and receives a message from the MMEthat a new PDN connection is needed, the UE may use an APN in the UErequested PDN connectivity procedure that is different from the APNscorresponding to the LIPA PDN connections.

In other embodiments, the MME sends a SERVICE REJECT message andindicates that “No PDP Context Activated” if the MME/network receives aSERVICE REQUEST from a UE in a cell that is not a CSG cell and the MMEdetermines that the UE has at least one LIPA PDP context, or if theMME/network receives a SERVICE REQUEST from a UE in a CSG cell with aCSG identity different from the CSG identity of the cell where the UEactivated the LIPA PDP context or PDP contexts. In response, the UEdeactivates locally all active PDP and MBMS contexts, and enters thestate GMM-REGISTERED.NORMAL-SERVICE. The UE may also activate PDPcontext(s) to replace any previously active PDP contexts, and may alsoperform the procedures needed in order to activate any previously activemulticast service(s). If the UE has only LIPA PDP contexts when theMME/network indicates that “No PDP Context Activated” and if the UEactivates PDP context(s) to replace any previously active PDP contexts,the UE should not request a LIPA PDP context in the ACTIVATE PDP CONTEXTREQUEST. Ifa specific APN is used for LIPA, the UE should use an APN inthe ACTIVATE PDP CONTEXT REQUEST message that is different from the APNscorresponding to the LIPA PDP contexts.

In other embodiments, the MME sends a SERVICE REJECT message andindicates Implicitly Detached if the network received a SERVICE REQUESTfrom a UE in a CSG cell with a CSG identity different from the CSGidentity of the cell where the UE activated the LIPA PDP context or PDPcontexts, or if the MME received the SERVICE REQUEST from a UE in a CSGcell with a CSG identity different from the CSG identity of the cellwhere the UE activated the LIPA PDN connection or LIPA PDN connections,or if the UE sends a SERVICE REQUEST from a cell that is not a CSG celland the UE has at east one LIPA PDN connection. In response, the UEdeletes the list of equivalent PLMNs and enters the stateEMM-DEREGISTERED.NORMAL-SERVICE. The UE deletes any mapped EPS securitycontext or partial native EPS security context, and then performs a newattach procedure. If the UE has only LIPA PDN connections when the UEreceives an “Implicitly Detached” message, the UE may use an APN in theattach procedure that is different from the APNs corresponding to theLIPA PDN connections. If A/Gb mode or lu mode is supported by the UE,the UE also handles the GMM state for the case when the combined routingarea updating procedure is rejected with the GMM cause with the samevalue. As will be appreciated, a UE in CS/PS mode 1 or CS/PS mode 2 ofoperation is still IMSI attached for non-EPS services.

If connectivity with the requested PDN is accepted, the MME 2008 storesthe CSG identity of the cell where the MME 2008 received the PDNCONNECTIVITY REQUEST message from the UE 2002. Similarly, if the MME2008 accepts the requested PDP context in a CSG cell, the MME 2008stores the CSG identity of the cell where the UE activated the PDPcontext. At signal flows 20-4 through 20-0, PDN connection establishmentprocedure is performed as indicated. On completion of PDN connectionestablishment procedure, MME 2008 initiates LIPA PDN connection releaseprocedure (signal flow 20-10).

Embodiments: UE is RRC connected by only signaling bearers are createdlnaccordance with selected embodiments, another solution is describedwhich addresses the cases of NAS idle mode mobility where the UE movesfrom a HeNB to GERAN/UTRAN. In this solution, a UE sends a TAU requestto the MME from a cell for which LIPA/SIPTO service continuity is notprovided for a LIPA PDN connection previously established in a HeNB.Upon receiving the TAU request message from the UE, the MME eitherperforms the TAU procedure without releasing the LIPA PDN connections incase the UE goes back to the HeNB, or it releases them (which mayinclude rejecting the TAU and order the UE to disconnect and re-attach).In selected embodiments, if the MME determines that the UE has at leastone PDN connection that is not a LIPA PDN connection and at least oneLIPA PDN connection, and the MME has received a TRACKING AREA UPDATEREQUEST message from the UE in a cell that is not a CSG cell or a CSGcell with a different CSG identity than the previous CSG cell or in acell that is not a CSG cell, and if the MME determines that the UE isRRC connected but only signaling bearers are created during the trackingare update procedure, the MME accepts the tracking area update request.

The applied assumptions in this case are that (1) Service Continuity forthe LIPA is not supported, (2) UE had at least one LIPA connectionbefore it enters into IDLE mode, (3) UE is in ECM-IDLE mode before theUE initiates TAU, (4) UE is connected to a cell where LIPA/SIPTO servicecontinuity is not provided when the UE initiates TAU procedure, AND (5)TAU is initiated either because TAU timer expires or because the UEenters into a new TA while the UE is in IDLE mode.

TAU Update Without PDN Release

In selected embodiments for providing a TAU update without PDN release,the UE is in RRC connected mode and ECM idle mode when sending the TAU.In this case, only radio signaling bearers are created, and the MMEperforms TAU update without releasing any PDN connection since the UE isin IDLE mode since the UE may go back to the HeNB's coverage before itchanges into CONNECTED mode. In this embodiment, disconnection of thePDN is delayed. The MME decision may depends on several factors such astime duration that UE has been in IDLE mode, if the UE stays in the sameTA that the HeNB belongs, etc.

MME Releases PDN Connections

In selected embodiments where the MME releases PDN connections, the MMEreleases LIPA/SIPTO PDN connection(s) as the UE is currently connectedto a cell where LIPA/SIPTO service continuity is not provided. In thiscase, if the MME decision to release LIPA/SIPTO PDN connections resultsin no remaining PDN connection for the UE, the MME will reject the TAURequest with cause “No EPS bearer context activated.” If so, the UE willrelease its context information and re-attach to the network, whichinvolves new PDN connection establishment.

In accordance with selected embodiments, another solution is describedwhich addresses the case of NAS idle mode mobility where the UE movesfrom a HNB to GERAN/UTRAN. In this solution, a UE sends a RAU request toa new SGSN. In reply, if the SGSN has no context information for the UE,the SGSN sends a Context Request message to the old MME or the old SGSN.The old MME or the old SGSN responds with a Context Response message anddecides whether or not to convey the information regarding the LIPA PDNconnection or LIPA PDP context based on an algorithm defined in thedetails below.

The applied assumptions in this case are that (1) Service Continuity forthe LIPA PDN connection is not supported, and (2) UE had at least onePDN connection which is LIPA PDN connection before it enters into IDLEmode.

In operation, the new SGSN responds to an RAU request from a UE bysending a Context Request message to the old SGSN or old MME. The oldSGSN/MME responds with a Context Response message. In the ContextResponse message, the MME/SGSN UE EPS PDN Connections IE containsdetailed information regarding the active PDN connections and theircorresponding EPS bearers for the UE. The MME/SGSN may or may notinclude the context information corresponding to the LIPA PDNconnections/PDP contexts. The MME decision of whether to convey thecontext information of the LIPA PDN connection is as follows. If eitherLIPA service continuity is supported or the MME determines that the newSGSN is capable of handling LIPA services (i.e., the SGSN is Rel. 10 orlater Release), then the MME conveys LIPA PDN context information.Otherwise, the MME does not convey LIPA PDN context information. If theMME or the old SGSN does not convey LIPA PDN connection or LIPA PDPcontext information to the new SGSN, the new SGSN initiates the PDPcontext disconnection procedure for the LIPA PDP contexts in order tokeep state information synchronized.

If the SGSN determines that the UE has at least one PDP context that isnot a LIPA PDP context and that the UE has at least one LIPA PDPcontext, and the SGSN has received a ROUTING AREA UPDATE REQUEST messagefrom the UE in a cell that is not a CSG cell or a CSG cell with adifferent CSG identity than the CSG cell where the LIPA PDP contextswere activated, and if the UE is RRC connected but only signalingbearers are created during the tracking are update procedure, then theSGSN accepts the routing area update request.

Embodiments: Selected CSFB with PS HO Another solution is described thataddresses the case of handovers to GERAN/UTRAN that are triggered by CSFallback with PS HO. In this network-based solution, the MME performsthe handover preparation and execution during the CSFB procedure onlyfor the non-LIPA PDN connections.

In operation, if the UE has one or more active PDN connections inaddition to one or more LIPA PDN connections, then pursuant totriggering the PS HO to GERAN/UTRAN during the CSFB procedure, the MMEperforms handover preparation and execution only for the non-LIPA PDNconnections and the MME requests RAB allocation in the target systemonly for the non-LIPA connections or for all the PDN connectionsexcluding the LIPA PDN connection or by not requesting RAB allocation inthe target system for LIPA PDN connections. After the UE is redirectedto GERAN/UTRAN, the MME releases the LIPA PDN connections. In anotherembodiment, pursuant to triggering the handover the MME starts a timerT_O. The MME releases the LIPA PDN connections when the timer T_Oexpires and the UE has not performed the CSFB procedures for returningto E-UTRAN.

Embodiments: CSFB with no PS HO for GERAN with no DTM target cell and UEresumes PS traffic in E-UTRANIn accordance with selected embodiments,additional solutions are provided to address the case of CSFB with no PSHO where the UE resumes PS traffic in HeNB, and addresses the hysteresiswith delay disconnection of LIPA connections. In this network-basedsolution, the MME disconnects the LIPA PDN connections after the CSservice has terminated only if the UE returns to E-UTRAN, to a macrotarget cell, or a different HeNB for which LIPA PDN continuity shall notbe supported. In these embodiments, there is no DTM target cell and theUE resume PS traffic in E-UTRAN.

In a first embodiment, the solution applies to a UE that performs CSFBprocedures and moves to a target GERAN network or cell that does notsupport dual transfer mode (DTM), or to a UE that does not support DTM.In this case, the MME disconnects the LIPA PDN connections only if theUE performs the CSFB procedures for returning to E-UTRAN and returns toa E-UTRAN cell that is not a CSG cell or to a E-UTRAN CSG cell for whichLIPA PDN continuity is not supported (such as a E-UTRAN CSG cell with aCSG ID different from the CSG cell where the LIPA PDN connections werecreated). In this solution, pursuant to the UE triggering CSFBprocedures and the PS Handover not being supported or the target networkor target cell being a GERAN network or cell that does not support DTMor the UE not supporting DTM, the MME stores the CSG ID of the E-UTRANcell where the UE triggers the CSFB procedure. The MME maintains suchinformation until the UE returns to E-UTRAN or the UE resumes the PSbearers in GERAN/UTRAN.

On the other hand, if the UE sends NAS signaling to the MME in order toresume the service in E-UTRAN according to current CSFB procedures, thenthe MME verifies if the UE is resuming the services from a cell with thesame CSG ID that the MME stored upon the UE executing the fallbackprocedure. If services are being resumed from a cell with a differentCSG ID or services are resumed from a non-CSG cell or a cell without aCSG ID, then the MME disconnects the LIPA PDN connections. Otherwise,the MME does nothing.

In another embodiment, the MME starts a timer T when the UE suspends thebearer during the fallback procedure. Pursuant to the timer T expiring,if the UE has not performed the CSFB procedures for returning to E-UTRANor the PS bearers are still suspended, then the MME disconnects the LIPAPDN connections.

In this solution, pursuant to the UE triggering CSFB procedures and thePS Handover not being supported or the target network or target cellbeing a GERAN network or cell that does not support DTM or the UE notsupporting DTM, the MME starts a timer T-P2 and the MME stores the CSGID of the E-UTRAN cell where the UE triggers the CSFB procedure. The MMEmaintains the CSG ID information until the UE returns to E-UTRAN or theUE resumes the PS bearers in GERAN/UTRAN. Pursuant to the timer T_P2expiring, if the UE has not performed the CSFB procedures for returningto E-UTRAN or the PS bearers are still suspended, then the MMEdisconnects the LIPA PDN connections. In addition, if the UE sends NASsignaling to the MME in order to resume the service in E-UTRAN accordingto current CSFB procedures before the timer T_P2 expires, then the MMEresets the time and the MME verifies if the UE is resuming the servicesfrom a cell with the same CSG ID that the MME stored upon the UEexecuting the fallback procedure. If services are being resumed from acell with a different CSG ID or services are resumed from a non-CSG cellor a cell without a CSG ID, then the MME disconnects the LIPA PDNconnections. Otherwise, the MME does nothing.

Embodiments: CSFB with no PS HO and UE resumes PS traffic inGERAN/UTRANIn accordance with selected embodiments, additional solutionsare provided to address the case of handovers to GERAN/UTRAN triggeredby CS Fallback without PS HO where the UE resumes PS traffic inGERAN/UTRAN. In this solution, the UE performs NAS signaling overGERAN/UTRAN to resume the suspended PS bearers.

In operation, the MME responds to the received CONTEXT REQUEST messagefrom the new SGSN by sending a CONTEXT RESPONSE message. When the MMEsends CONTEXT RESPONSE to the target SGSN, the MME omits the informationregarding LIPA/SIPTO PDN connection(s) so that the target SGSN does notcreate a PDP context for the corresponding LIPA PDN connection. However,the solution is triggered by the UE performing NAS signaling overGERAN/UTRAN to resume the suspended PS bearers.

Embodiments: Handover to GERAN/UTRAN triggered by CS FallbackInaccordance with selected embodiments, additional solutions are describedwith reference to FIG. 16, and address the case of handovers toGERAN/UTRAN triggered by CS Fallback when there is no PS HO and there isa mobile terminated call. In operation, a UE 2102 that has only LIPA PDNconnections active triggers the PS HO to GERAN/UTRAN during the CSFBprocedure. In response, the MME 2108 decides that no PS HO shall beperformed for the PS bearers, based on the fact that the target cell isGERAN/UTRAN and that the UE has only LIPA PDN connections. After the UE2102 is redirected to GERAN/UTRAN, the MME 2108 keeps the UE contextinformation until UE performs RAU.

As described below, a second example embodiment differs from the firstone in terms of when the MME initiated the cell reselection procedure.The second example embodiment covers in addition the general case ofinter-RAT handover.

In a selected embodiment, the UE 2102 has only LIPA/SIPTO PDNconnections. When the HO from the HeNB 2104 to GERAN/UTRAN is triggereddue to CSFB, Initial UE Context Setup Request from MME 2108 to HeNB 2104indicates that the PS HO is not available. HeNB 2104 informs the UE 2102to move into the target GERAN/UTRAN cell, either by using NetworkAssisted Cell Change or by triggering RRC signaling connection releasewith redirection to GERAN/UTRAN.

At signal flow 21-1, the MME 2108 receives a Paging Request (IMSI, VLRTMSI, Location Information) message from the MSC 2112 over a SGsinterface. The MME 2108 then pages the UE in all the TAs.

At signal flow 21-2, the MME 2108 sends a Paging message to each eNodeB.The Paging message includes a suitable UE Identity (i.e. S-TMSI or IMSI)and a CN Domain Indicator that indicates which domain (CS or PS)initiated the paging message. In this case it shall be set to “CS” bythe MME.

At signal flow 21-3, the radio resource part of the paging proceduretakes place whereby the eNodeB 2104 sends the paging message to the UE2102. The message contains a suitable UE Identity (i.e. S-TMSI or IMSI)and a CN Domain indicator.

At signal flow 21-4, the UE 2102 establishes an RRC connection and sendsan Extended Service Request (CS Fallback Indicator) to MME 2108. The UE2102 indicates its S-TMSI in the RRC signaling. The Extended ServiceRequest message is encapsulated in RRC and S1-AP messages. The CSFallback Indicator indicates to the MME that CS Fallback for this UEshould be performed. In case of Mobile Originated (MO) CSFB, signal flow21-1 through 21-3 are not performed.

At signal flow 21-5, the MME 2108 sends the SGs Service Request messageto the MSC 2112 containing an indication that the UE 2102 was in idlemode (and hence, for example, that the UE has not received any CallingLine Identification information). Receipt of the SGs Service Requestmessage stops the MSC 2112 from retransmitting the SGs interface Pagingmessage.

At signal flow 21-6, the MME 2108 sends S1-AP: Initial UE Context Setup(UE capabilities, CS Fallback Indicator and other parameters) to notifyeNodeB to move the UE 2102 to UTRAN/GERAN. The MME 2108 determines thatPS HO cannot be performed based on the fact that the UE has only LIPAPDN connections and the LIPA service continuity is not supported andindicates in this message that PS HO is not available for the UE 2102.The eNB shall reply with S1-AP: Initial UE Context Setup Responsemessage (not shown). As HeNB 2104 determines that PS HO is notavailable, the HeNB 2104 performs either signal flow 21-7 a or 21-7 binstead of sending HO REQUIRED message to the MME 2108.

In signal flow 21-7 a, if the target cell is GERAN, the HeNB 2104 cantrigger an inter-RAT cell change order (optionally with Network AssistedCell Change (NACC)) to a GERAN neighbor cell by sending an RRC messageto the UE 2102. The inter-RAT cell change order may contain a CSFallback Indicator which indicates to UE 2102 that the cell change orderis triggered due to a CS fallback request.

In signal flow 21-7 b, the HeNB 2104 can trigger RRC connection releasewith redirection to GERAN or UTRAN instead of PS HO or NACC. If the UE2102 and network support “RRC connection release with redirection andMulti Cell System Information to GERAN/UTRAN”, the HeNB 2104 can triggerRRC connection release with redirection to GERAN or UTRAN and includeone or more physical cell identities and their associated SystemInformation.

At signal flow 21-8, the UE establishes the RRC connection and thenperforms the rest of procedure for CSFB which may include RAU. As it ispossible that the target SGSN 2110 sends CONTEXT REQUEST message to thesource MME 2108 as a part of RAU procedure, the MME 2108 does notrelease the context information of the UE 2102 until it receives theCONTEXT REQUEST message. On receiving the CONTEXT REQUEST message, theMME 2108 returns CONTEXT RESPONSE with zero active PDN connections andimplicitly detaches the UE 2102 from the network.

In accordance with selected embodiments, additional solutions aredescribed with reference to FIG. 17 for the case where the UE 2202 hasonly LIPA/SIPTO PDN connections. In this procedure signal flows 22-1through 22-6 in FIG. 17 are similar to signal flows 21-1 through 21-6 inFIG. 16. However, instead of receiving the information that PS HO is notavailable for the UE in the Initial UE Context Setup message, thisinformation (that PS HO is not available for the UE) is delivered to theHeNB 2204 on the HO PREPARATION FAILURE message (at signal flow 22-8)after sending the HO REQUIRED to the MME 2208 (at signal flow 22-7). Thecause value of the HO PREPARATION FAILURE message will be “PS HO NotAvailable.” Though this solution may include one more message handshakerounds, this solution can be reused for the case of IRAT HO due to UE'smobility.

In accordance with selected embodiments, additional solutions aredescribed for the case of a UE/mobile originating or UEimobileterminating CSFB call procedure when PS HO is not supported and wherethe UE has only LIPA PDN connections. This procedure is illustrated withreference to the signal flow for a CS Call Request in E-UTRAN or Call inGERAN/UTRAN without PS HO depicted in FIG. 6.3-1 of 3GPP TS 23.272.According to this solution, the UE receives as signal 3 b an RRCconnection release from the eNodeB with redirection to GERAN or UTRAN ifthe HeNB determines that the UE only has LIPA PDN connections based onthe existence of a Correlation Identifier (ID). In this solution, if thePDN connection is established for LIPA, the S1 control message signal 1b from the MME to the HeNB includes a Correlation ID per EPS bearer forenabling the direct user plane path between the HeNB and the L-GW. InRelease 10 of the 3GPP specification, the Correlation ID is set equal tothe user plane PDN GW TEID (GTP-based S5) or GRE key (PMIP-based S5 ).Thus, the detecting by the HeNB of the Correlation ID in the S1 controlmessage from the MME indicates that the corresponding EPS bearer is forLIPA.

Embodiments: Subscription ProfileIn accordance with selectedembodiments, additional solutions are provided which address the caseswhere the UE has the ability to know whether there is session continuityfor LIPA PDN connections. In these solutions, the UE is provided anindication of the support for LIPA continuity by the SGSN MME duringattach/PDN connection activation, and the SGSN/MME decides whether tomaintain the connection automatically or based on the subscriptionprofile (such as on a per-APNs basis).

In this solution if the service continuity support information ispresent for an APN and indicates that service continuity shall besupported, then the MME or SGSN shall allow the service continuity whenthe UE moves between a H(e)NB cell or a CSG cell and a macro cell or acell that is not a CSG cell. If the service continuity supportinformation indicates that service continuity shall not be supported,then the MME or SGSN shall not allow the service continuity. If theservice continuity support information for is not present, the MME orSGSN shall allow the service continuity when the UE moves towards anycell.

As described below, there are three components to the disclosedsolution.

First, the subscription profiles include an indication of support forLIPA continuity, wherein the HPLMN indicates to the VPLMN which APNssupport session continuity.

Second, the MME verifies upon attach and PDN connection establishmentwhether the PDN connection to a certain APN can support LIPA continuity.In addition, the SGSN verifies upon PDP context creation whether the PDNconnection to a certain APN can support LIPA continuity. Theverification by the MME/SGSN is performed as follows. If the UEsubscription profile contains a CSG Service Continuity, and if the CSGID of the current H(e)NB is in the list of CSG IDs in the CSG ServiceContinuity, LIPA service continuity is allowed for all APNs in thecurrent H(e)NB. However, if the CSG ID of the current H(e)NB is not inthe list of CSG IDs in the CSG Service Continuity, or if the UEsubscription profile does not contain a CSG Service Continuity, then theMME checks the Service Continuity Support field in the subscriptioninformation for the current APN (for which the connectivity is beingrequested). If the field indicates it is supported, or if the filedcontains a list of the CSG IDs and the CSG ID of the current cell isamong those, then LIPA service continuity is supported

Third, the SGSN/MME indicates to the UE whether LIPA is continuity isprovided. For example, the SGSN indicates to the UE whether LIPAcontinuity for a PDP context upon PDP context activation based on theconditions above. In addition or in the alternative, the MME indicatesto the UE whether LIPA continuity for a PDN connection upon PDNconnection activation based on the conditions above. In addition or inthe alternative, the MME indicates to the UE whether LIPA continuity forany PDN connection upon attach based on the conditions above. Inaddition or in the alternative, the MME indicates to the UE whether LIPAcontinuity for the one or more PDN connections upon the UE performing atracking area update or combined tracking area update based on theconditions above.

In support of the disclosed solution, a service continuity supportparameter indicates if service continuity for LIPA PDN connections issupported upon idle mode or connected mode mobility between cells forthe corresponding to a PDN connection requested by the UE with a LIPAAPN or with a request for connectivity type “LIPA.” If LIPA connectivityis prohibited on that PDN, the value will be always true. Servicecontinuity support can be scalar binary or two dimensional binary flagsto indicate in-bound service continuity and out-bound servicecontinuity. If in-bound service continuity flag is “true,” servicecontinuity will be provided when the UE moves into H(e)NB sub-system. Ifout-bound service continuity flag is “true,” service continuity will beprovided when the UE moves out of H(e)NB sub-system. The indicator canalso contain a list of CSG IDs in which service continuity is supportedfor the APN. Service continuity support is permanent data and isconditionally stored in the HSS. MME and SGSN. In addition, the servicecontinuity support parameter may be included as data used for PS NetworkAccess Mode (GPRS), as well as other appropriate tables, such as Table5.2 (Overview of data used for PS Network Access Mode (GPRS)) and Table5.2A-1: (Overview of data used for PS Network Access Mode (EPS 3GPPaccess)) in 3GPP TS 23.008 (“Organization of Subscriber Data”), andTable 7.3.1/1 (S6a/S6d and S13/S13′ specific Diameter AVPs) in 3GPP TS29.272 (“Evolved Packet System (EPS); Mobility Management Entity (MME)and Serving GPRS Support Node (SGSN) related interfaces based onDiameter protocol”).

In selected embodiments, the service continuity support AVP is of typeGrouped, and contains two service continuity flag AVPs, where the firstflag is the inbound service continuity support flag and the second flagis the out-bound service continuity support flag. The AVP format in thiscase is as follows:

Service continuity support ::=<AVP header: 1613 10415>

[Service continuity flag]

[Service continuity flag]

In other embodiments, the service continuity flag AVP is of typeunsigned32, and indicates if service continuity in one direction for theconnection is supported when the UE moves between a H(e)NB cell and amacro cell or a H(e)NB cell that belongs to differentResidential/Enterprise network. In this case, the following servicecontinuity flag values are defined: (1) Service continuity is notsupported (0), and (2) Service continuity is supported (1).

PDN Address

The purpose of the PDN address information element is to assign an IPv4address to the UE associated with a packet data network and to providethe UE with an interface identifier to be used to build the IPv6 linklocal address. The PDN address information element is coded as shown inTables 3 and 4 below.

Table 3: PDN address information element

As shown above in Table 3, the PDN address is a type 4 informationelement with minimum length of 7 octets and a maximum length of 15octets.

TABLE 4 PDN address information element PDN type value (octet 3) Bits 32 1 0 0 1 IPv4 0 1 0 IPv6 0 1 1 IPv4v6 All other values are reserved.Bit 4 to 8 of octet 3 are spare and shall be coded as zero. PDN addressinformation (octet 4 to 15) If PDN type value indicates IPv4, the PDNaddress information in octet 4 to octet 7 contains an IPv4 address. Bit8 of octet 4 represents the most significant bit of the IPv4 address andbit 1 of octet 7 the least significant bit. If PDN type value indicatesIPv6, the PDN address information in octet 4 to octet 11 contains anIPv6 interface identifier. Bit 8 of octet 4 represents the mostsignificant bit of the IPv6 interface identifier and bit 1 of octet 11the least significant bit. If PDN type value indicates IPv4v6, the PDNaddress information in octet 4 to octet 15 contains an IPv6 interfaceidentifier and an IPv4 address. Bit 8 of octet 4 represents the mostsignificant bit of the IPv6 interface identifier and bit 1 of octet 11the least significant bit. Bit 8 of octet 12 represents the mostsignificant bit of the IPv4 address and bit 1 of octet 15 the leastsignificant bit. If PDN type value indicates IPv4 or IPv4v6 and DHCPv4is to be used to allocate the IPv4 address, the IPv4 address shall becoded as 0.0.0.0.

Referring now to FIG. 18, there is shown a schematic block diagramillustrating exemplary components of a mobile wireless communicationsdevice 101 which may be used with selected embodiments of the presentdisclosure. The wireless device 101 is shown with specific componentsfor implementing features described above. It is to be understood thatthe wireless device 101 is shown with very specific details forexemplary purposes only.

A processing device (e.g., microprocessor 128) is shown schematically ascoupled between a keyboard 114 and a display 127. The microprocessor 128controls operation of the display 127, as well as overall operation ofthe wireless device 101, in response to actuation of keys on thekeyboard 114 by a user.

The wireless device 101 has a housing that may be elongated vertically,or may take on other sizes and shapes (including clamshell housingstructures). The keyboard 114 may include a mode selection key, or otherhardware or software for switching between text entry and telephonyentry.

In addition to the microprocessor 128, other parts of the wirelessdevice 101 are shown schematically. These include a communicationssubsystem 171; a short-range communications subsystem 102; the keyboard114 and the display 127, along with other input/output devices includinga set of LEDs 104, a set of auxiliary I/O devices 106, a serial port108, a speaker 111 and a microphone 112; as well as memory devicesincluding a flash memory 116 and a Random Access Memory (RAM) 118; andvarious other device subsystems 122. The wireless device 101 may have abattery 121 to power the active elements of the wireless device 101. Thewireless device 101 is in some embodiments a two-way radio frequency(RF) communication device having voice and data communicationcapabilities. In addition, the wireless device 101 in some embodimentshas the capability to communicate with other computer systems via theInternet.

Operating system software executed by the microprocessor 128 is in someembodiments stored in a persistent store, such as the flash memory 116,but may be stored in other types of memory devices, such as a read onlymemory (ROM) or similar storage element. In addition, system software,specific device applications, or parts thereof, may be temporarilyloaded into a volatile store, such as the RAM 118. Communication signalsreceived by the wireless device 101 may also be stored to the RAM 118.

The microprocessor 128, in addition to its operating system functions,enables execution of software applications on the wireless device 101. Apredetermined set of software applications that control basic deviceoperations, such as a voice communications module 131A and a datacommunications module 131B, may be installed on the wireless device 101during manufacture. In addition, a personal information manager (PIM)application module 131C may also be installed on the wireless device 101during manufacture. The PIM application is in some embodiments capableof organizing and managing data items, such as e-mail, calendar events,voice mails, appointments, and task items. The PIM application is alsoin some embodiments capable of sending and receiving data items via awireless network 113. In some embodiments, the data items managed by thePIM application are seamlessly integrated, synchronized and updated viathe wireless network 113 with the device user's corresponding data itemsstored or associated with a host computer system. As well, additionalsoftware modules, illustrated as another software module 131N, may beinstalled during manufacture.

Communication functions, including data and voice communications, areperformed through the communication subsystem 171, and possibly throughthe short-range communications subsystem 102. The communicationsubsystem 171 includes a receiver 151, a transmitter 152 and one or moreantennas, illustrated as a receive antenna 154 and a transmit antenna156. In addition, the communication subsystem 171 includes a processingmodule, such as a digital signal processor (DSP) 158, and localoscillators (LOs) 161. In some embodiments, the communication subsystem171 includes a separate antenna arrangement (similar to the antennas 154and 156) and RF processing chip/block (similar to the Receiver 151, LOs161 and Transmitter 152) for each RAT, although a common baseband signalprocessor (similar to DSP 158) may be used for baseband processing formultiple RATs. The specific design and implementation of thecommunication subsystem 171 is dependent upon the communication networkin which the wireless device 101 is intended to operate. For example,the communication subsystem 171 of the wireless device 101 may bedesigned to operate with the Mobitex™, DataTAC™ or General Packet RadioService (GPRS) mobile data communication networks and also designed tooperate with any of a variety of voice communication networks, such asAdvanced Mobile Phone Service (AMPS), Time Division Multiple Access(TDMA), Code Division Multiple Access (CDMA), Personal CommunicationsService (PCS), Global System for Mobile Communications (GSM), etc.Examples of CDMA include 1X and 1x EV-DO. The communication subsystem171 may also be designed to operate with an 802.11 Wi-Fi network or an802.16 WiMAX network or both. Other types of data and voice networks,both separate and integrated, may also be utilized with the wirelessdevice 101.

Network access may vary depending upon the type of communication system.For example, in the Mobitex™ and DataTAC™ networks, wireless devices areregistered on the network using a unique Personal Identification Number(PIN) associated with each device. In GPRS networks, however, networkaccess is typically associated with a subscriber or user of a device. AGPRS device therefore typically has a subscriber identity module,commonly referred to as a Subscriber Identity Module (SIM) card, inorder to operate on a GPRS network.

When network registration or activation procedures have been completed,the wireless device 101 may send and receive communication signals overthe communication network 113. Signals received from the communicationnetwork 113 by the receive antenna 154 are routed to the receiver 151,which provides for signal amplification, frequency down conversion,filtering, channel selection, etc., and may also provide analog todigital conversion. Analog-to-digital conversion of the received signalallows the DSP 158 to perform more complex communication functions, suchas demodulation and decoding. In a similar manner, signals to betransmitted to the network 113 are processed (e.g., modulated andencoded) by the DSP 158 and are then provided to the transmitter 152 fordigital to analog conversion, frequency up conversion, filtering,amplification and transmission to the communication network 113 (ornetworks) via the transmit antenna 156.

In addition to processing communication signals, the DSP 158 providesfor control of the receiver 151 and the transmitter 152. For example,gains applied to communication signals in the receiver 151 and thetransmitter 152 may be adaptively controlled through automatic gaincontrol algorithms implemented in the DSP 158.

In a data communication mode, a received signal, such as a text messageor web page download, is processed by the communication subsystem 171and is input to the microprocessor 128. The received signal is thenfurther processed by the microprocessor 128 for an output to the display127, or alternatively to some other auxiliary L/O devices 106. A deviceuser may also compose data items, such as e-mail messages, using thekeyboard 114 and/or some other auxiliary I/O device 106, such as atouchpad, a rocker switch, a thumb-wheel, or some other type of inputdevice. The composed data items may then be transmitted over thecommunication network 113 via the communication subsystem 171.

In a voice communication mode, overall operation of the device issubstantially similar to the data communication mode, except thatreceived signals are output to a speaker 111, and signals fortransmission are generated by a microphone 112. Alternative voice oraudio I/O subsystems, such as a voice message recording subsystem, mayalso be implemented on the wireless device 101. In addition, the display127 may also be utilized in voice communication mode, for example, todisplay the identity of a calling party, the duration of a voice call,or other voice call related information.

The short-range communications subsystem 102 enables communicationbetween the wireless device 101 and other proximate systems or devices,which need not necessarily be similar devices. For example, the shortrange communications subsystem may include an infrared device andassociated circuits and components, or a Bluetooth™ communication moduleto provide for communication with similarly-enabled systems and devices.

It should be understood that as used herein, terms such as coupled,connected, electrically connected, in signal communication, and the likemay include direct connections between components, indirect connectionsbetween components, or both, as would be apparent in the overall contextof a particular embodiment. The term coupled is intended to include, butnot be limited to, a direct electrical connection.

Although the described exemplary embodiments disclosed herein aredescribed with reference to selected communication systems, the presentdisclosure is not necessarily limited to the example embodiments whichillustrate inventive aspects of the present disclosure that areapplicable to a wide variety of network connectivity arrangements. Thus,the particular embodiments disclosed above are illustrative only andshould not be taken as limitations upon the present disclosure, as thedisclosure may be modified and practiced in different but equivalentmanners apparent to those skilled in the art having the benefit of theteachings herein. Accordingly, the foregoing description is not intendedto limit the disclosure to the particular form set forth, but on thecontrary, is intended to cover such alternatives, modifications andequivalents as may be included within the spirit and scope of thedisclosure as defined by the appended claims so that those skilled inthe art should understand that they can make various changes,substitutions and alterations without departing from the spirit andscope of the disclosure in its broadest form.

What is claimed is:
 1. A user equipment (UE) comprising: a memory; and aprocessor coupled to the memory, the processor to, while the UE has atleast one Packet Data Network (PDN) connection comprising local internetprotocol access (LIPA) connectivity at a first cell having a firstClosed Subscriber Group (CSG) identity: perform a Circuit-SwitchedFallback (CSFB) procedure without Packet Switched (PS) handover to movethe UE to a second cell; send a Non Access Stratum (NAS) message toresume Evolved Universal Terrestrial Radio Access Network (E-UTRAN)service from a third cell having a second CSG identity, where the thirdcell has no service continuity for the at least one PDN connection; andreceive a DEACTIVATE EPS BEARER CONTEXT REQUEST message to release theat least one PDN connection responsive to the third cell having noservice continuity for the at least one PDN connection.
 2. The UE ofclaim 1, where performing the CSFB procedure without PS handover movesthe UE to the second cell which is a E-UTRAN cell that is not a CSG cellor that has a CSG identity that is different from the first CSG identityof the first cell.
 3. A method for use in a user equipment (UE) havingat least one Packet Data Network (PDN) connection comprising localinternet protocol access (LIPA) connectivity at a first cell having afirst Closed Subscriber Group (CSG) identity, the method comprising:performing a Circuit-Switched Fallback (CSFB) procedure without PacketSwitched (PS) handover to move the UE to a second cell; sending a NonAccess Stratum (NAS) message to resume Evolved Universal TerrestrialRadio Access Network (E-UTRAN) service from a third cell having a secondCSG identity, where the third cell has no service continuity for the atleast one PDN connection; and receiving a DEACTIVATE EPS BEARER CONTEXTREQUEST message to release the at least one PDN connection responsive tothe third cell having no service continuity for the at least one PDNconnection.
 4. The method of claim 3 where the UE comprises a Non-AccessStratum (NAS) layer, an Access Stratum (AS) layer, and an applicationlayer.
 5. The method of claim 3, further comprising starting a timerwhen the UE enters NAS idle mode having at least one active LIPA PDNconnection, where the UE sends the NAS message after the timer expiresonly if the first CSG identity of the first cell and the second CSGidentity of the third cell are different.
 6. The method of claim 3,where performing the CSFB procedure without PS handover moves the UE tothe second cell which is a E-UTRAN cell that is not a CSG cell or thathas a CSG identity that is different from the first CSG identity of thefirst cell.